I was thinking of funding a school of low magic, for basic Services.  (I am playing a high level mass game that does a bit of downtime stuff.)

I was thinking of giving magic to the masses, like a vocational school. Something focused on beneficial spells that can be used in professions, and everyday life.

Who teaches cantrips????? Does it have to be high level? What kind of building would I need? 

To begin with I was thinking Mending, Mold earth (irrigation projects, building etc), Control flames (firebrigade). Maybe research new "day to day" spells and 

Sounds like you need some house rules. The closest official rule is Tasha's sidekick rules which just automatically make NPCs the same level as the party when they join (not helpful).

Level 1 players are assumed to have spent some time getting the basics of their class down in the backstory, but no specific amount of time is suggested. From level 1 it is just a matter of practicing and refining these basics to discover/create more advanced techniques and this is measured by experience. But that doesn't help here.

Yeah, just need to make some rules up. Maybe after 6 months of magic lessons they make a DC15 arcana check to see if they learned a cantrip or not.

Quote from Lambros >>

I was thinking of giving magic to the masses, like a vocational school. 

Who teaches cantrips????? Does it have to be high level? What kind of building would I need? 

 I think if it's something that's accessible to the masses, it wouldn't require someone that's too high-level. Think about how teaching public education in the real world requires a bit of higher education, but not to the degree of needing a doctorate like teaching university/college courses. 

You could have classes that would lead to players getting feats (and base the courses off the main parts of those feats). Then come up with a quirky personality for each of those class instructors. Some examples with curriculum examples: 

• Artificer Initiate -- intro to alchemy, smithing classes (think of it like home economics where the character's fav subsection leads to their tool proficiency, and they learn the mending cantrip)
• Magic Initiate --  make some curriculum based on the player classes that you have courses for, and pick signature spells for those
• Ritual Caster -- basics of arcane formulae, chanting/music classes

 You could expand further into things like Eldritch Adept (even if you limit it just to ones that give you access to spells, like mask of many faces).

Who taught you your cantrips? I would think that already exists. So maybe a talk with the Dm about making that a part of the game. I think there was some stuff about teaching magic in AD&D or maybe the Rules Cylopedia but it would still be house rules at this point.

I am an 11th level warlock... i do not think I can teach any cantrips till my 20th level when I can become a patron....

I see that my choice of spells are all transmutation, so at least there is no great need for a second tutor... 

I see that to add a library you need +2500, and to add a arcanist study 2500 per school, so those , 5000 + the building (30'*60' bacement+ground+floor)+ other furniture etc... should be something like 12000-15000 at a side street, in a poor neighbohood.... 

I prefer a poor neighborhood, but a main str might be better... It will have to be a discussion with the DM=waterdeep realtor :)

A total of 17-20.000 to begin with, 1 unskilled for errands and janitorial stuff, and a tutor.... I would imagine more than the minimum of skilled work... 10 times more? 

so lets say 8 gp/ month for the janitor, and 500gp for the tutor (5 day week) with 30 gp for student meals  and another 12 incidentals. +550/month, I could handle that....

I am planning to provide cold meal a day, and all of it to be free. But maybe I could have a 6 month supervised apprenticeship where I can have them in work groups.... and get some gp from irrigation projects or a mending shop....

 I made a bit of a floorplan... https://drive.google.com/file/d/1s-OxWIhx2l6f97lMMSuE9dmnJRQ18oyT/view?usp=sharing

https://www.tinkercad.com/things/8THeJ4MzbHC/edit

Sources 

library+study https://adventurers-guild.fandom.com/wiki/Housing_System

real estate https://hackmd.io/@palikhov/rJ9z223YU#:~:text=Class C: 2,000 gp per,)%20or%205%2C000%20gp%2Ffloor.

low price real estate https://docs.google.com/spreadsheets/d/1Gu47lsiU8P43dvtu97xThZDD0cp0RtgoA3fxqC00Sho/edit#gid=1804800390

other source or pricing- not too sure about it http://eberronunlimited.*******.com/building-a-stronghold

and another one more complicated https://www.reddit.com/r/WaterdeepDragonHeist/comments/pn1xyw/waterdeep_real_estate_prices_why_volo_gave/

I wouldn't call it socialist....seems odd to view it like that.

I would look at perhaps making your own spell variants.
Additionally, look at how they create spells for races in 5e and OneDnD to see if that can help you find the balance on the spells you're looking for.

If you're running with classes you could have spells as part of those classes regardless of the class. That way the spells you pick augment those classes without unbalancing them.

Cantrips would be really basic stuff. I view cantrips in such a setting like a primary school level teacher. Perhaps someone who can cast level 2 spells could be competent at teaching cantrips. I found this page that can give you an idea:
http://dmsworkshop.com/2021/09/10/dnd-101-tiers-levels/
Going off those tiers I would look at it like this:
Cantrips: level 1+
Level 1 spells: level 2+
.. Look at the wizard Character progression and base your teaching on when they get access to certain spell levels.
I wouldn't make this universal as some spells seems more powerful or more specialized at given levels than others of the same level.

In my opinion nameless NPCs labeled as "teachers" would be of sufficient level in a world where everyone knows magic at the cantrip level.

Ok, i looked again at what I want to pay for the tutor... and if cost of living between wealthy and aristocratic can be 4-10 gp, I am not going to pay more than 300 gp for full employment.

She will be teaching only cantrips, maybe researching new cantrips too...

@Lightsmith , thanks for the heads up! the name is just for the post, the actual name will be based on my character's name "Red" and the point of it is to bring magic to everyday life. Why dig a trench with workmen, when mold earth exists, why need a professional to repair shoes or clothes of a key, when mending exists, why run around with huge horse drawn barrels of water to take out fires if control flames exist, why spend money on flavoring spices when predigisticilisination (or whatever) exists....

I ran into this issue while making a world of my own, where an area has huge trade in lacquered woods, and I could not imagine why there is no spell to do the work...

Now I want to give back to the society , and I thought of free food or accommodation for the homeless, but the homeless do not really need a loaf of bread, they need a way to get out of their predicament. 

The school will be just for useful everyday low level magic, for anyone that wants it and it will be free, with one free cold meal per day of attendance (fruit and sandwich).

Let me flip the idea a bit - why isn’t there a spell/cantrip to do the work? Because then most folks would actually be out of work as everyone would be casting and not making things and trading/selling things to each other. Your entire economy breaks down.

I agree with you. It would probably mostly focus on cantrips and lower level spells that can be used by the general public.

Quote from Wi1dBi11 >>

Let me flip the idea a bit - why isn’t there a spell/cantrip to do the work? Because then most folks would actually be out of work as everyone would be casting and not making things and trading/selling things to each other. Your entire economy breaks down.

 Not really, there are already existing limitations on most cantrips that insure that, for example, prestidigitation would never take over using actual spices and seasonings in cooking because it only lasts a minute and repeatedly casting it during a meal is going to get really old.  Control Flame can only extinguish a single five-foot cube of fire per casting.  That's fine if the fire hasn't spread yet but you're going to still want to have a bucket brigade in a large fire unless everyone can cast it.  It also doesn't prevent reignition the way soaking an area down will.  Mold Earth can only be used to excavate loose dirt.  If you're working with any other type of soil, like clay or hardpan, or there are rocks mixed in, you're not getting very far.  Plus if you're trying to do something like construction you're going to need to do follow-up work to pack things down and reinforce the sides of the hole if you want it to remain stable.  Mending is fine for attaching an axe handled that was snapped off back together but it can't fix something that's worn out or rusted through.

Cantrips can augment manual labor, but as written most of them can't replace it.

I agree, in it will be a production boost in molding earth.

and in control flames you need a team to take control of a house fire.

In mending though you can have an amazing "handyman" for almost anything other than a serious issue.

but in spicing and warming the food you are not right in this: "seasonings in cooking because it only lasts a minute " it's an hour, so you can have unskilled laborers cooking, and a caster right before serving.

@wi1dbi11 it might be a disturbance, if I could fund a class of 100+ people, but i imagine that with an initial investment of 15-20k gps and a monthle less than 500gps i could have 1-2 classes of 15 people max. It will be a trickle in waterdeep, it will make some people upwardly mobile (squalid to poor definately and maybe modest too). In a decade there will be a new class of newly minted well off people. maybe 200 casters with their families will be no longer too poor to afford most everyday joy.

Right, an hour, not one minute.  It's still impractical because a caster can only have three non-instantaneous uses of Prestidigitation in effect at once.  Fine for one or two people but won't work out so well if you're running a pub or fixing a banquet.