Commoner

Not all heroes wear capes. Or armor. Or chainmail bikinis, or sweet robes and hats covered in velcro stars. Some heroes wear burlap. Or linen. Wool? Whatever it is commoners wear. These are survivors, generations of helpful townsfolk who have been guiding would-be heroes along their way for as long as there have been dice to roll! As a commoner, your never-say-die moxie and go-getter attitude has somehow led you into the jaws of adventure and danger. But we believe in you, even if your dad has his doubts.

(Not made by me, just ported to D&D Beyond and reworked slightly to help fit in D&D Beyond)

Sources:
Reddit user hakuna_dentata 
Google Commoner Class and it will be there.

Note: Read the rules and limitations inside of the class features. This is a class, pushed into a subclass because of D&D Beyond's limitations. It requires a few additional steps and changes sometimes.

Good Plain Folk

You are proficient in the use of artisan's tools as weapons, and add your expertise bonus when attacking with them.
They deal 1d4 of whatever damage type is appropriate for the tool.

 

Animal Handling

Animal Handling proficiency 

Athletics

Athletics proficiency

Insight

Insight proficiency

Persuasion

Persuasion proficiency

Survival

Survival proficiency

Gitter Done

Giving up never got anybody anywhere. You can give yourself advantage on any d20 roll by gritting your teeth and looking danger in the eye. You regain the use of this ability when you use your action to Improvise. (PHB pg 193)

The Darnedest Thing

Starting at 2nd level, you can survive the adventuring life through sheer coincidence. When you would be killed or reduced to 0 hp, you may tell the story (10 seconds or less) of how "the darnedest thing happened" that completely prevented the effect. You regain the use of this ability when you finish a long rest.

Sidekick

You're surrounded by badasses, why not be like them!? When you finish a long rest, pick an ally you can see. Choose

• One piece of equipment
• One skill
• One saving throw

with which that ally is proficient.

You gain those proficiencies until you choose a new ally or you spend more than 3 days without spending time with the chosen ally.

Questgiver

At 3rd level, whenever you finish a short or long rest, a bright yellow exclamation mark appears above your head. Choose up to three allies within 10 feet, and give them each one of the following:

• Main Plot Quest: Whenever your group completes an encounter that gives experience, you and the ally each heal for 1d6 per commoner level you have. Faint sparkles and a ding sound surround you.
• Kill Quest: Whenever you take the Attack or Help action against a creature, the ally can add your proficiency bonus to all damage rolls against that creature until the start of your next turn. You can Help the ally as a bonus action.
• Escort Quest: You and the ally each gain the effects of Warding Bond as if the other had cast it. These effects do not cancel one another, and only pass damage once.
• Boring Lore Quest: You or the ally can each reroll one attack, skill check, or saving throw relevant to your personalities, ideals, bonds, or flaws. You can also, at your DM's option, hold one additional Inspiration.

You can have no more than three active Quests, but you can duplicate or stack them as you see fit.

Warding bond -  While the target is within 60 feet of you, it gains a +1 bonus to AC and saving throws, and it has resistance to all damage. Also, each time it takes damage, you take the same amount of damage. The Damage does not double, you just both take damage with each other when having Escort Quest on.

 

Level 3

Here ya go

Commoner Combo!

Starting at 5th level, you're beginning to think you're good at this! And every real hero needs a kickass personal move list. When you hit with your artisan's tools, you can shout the name of a "special move" to add 5d4 damage to the attack and choose one of the following effects:

• You Shove the target.
• The target must make a DC 12 Dexterity save. If it fails, it is blinded, grappled, poisoned, or charmed (your choice) until the start of your next turn. Explain how your tools accomplished this effect.
• One ally gains advantage on their next attack against the target.
• You gain temporary hit points equal to your commoner level.

You can use this ability 3 times, and regain all uses after a short or long rest.

Note: Just like the base Artisans tools action, DO NOT FORGET TO ADD YOUR EXPERTISE BONUS TO HIT (this also applies to the upgraded versions later on if you get them)

Level 5

Here ya go

The Gosh Darnedest Thing

Starting at 6th level, you regain "The Darnedest Thing" when you finish a short or long rest.

Glass Half Full

Starting at level 7, when an attack or effect would inflict more than half of your current hp, it deals half your current hp (rounded up) instead.

This ability happens a number of times equal to 2 + your charisma modifier (ha), and refreshes when you finish a short or long rest.

Level 7

Here ya go

Waste Not, Want Not

By level 9, you have been collecting magical scrap and hand- me-downs and somehow cobbled them into something functional. You gain an uncommon magic item of your choice, subject to DM approval and ideally based on your artisan tools expertise.

You gain a new uncommon item at level 11, a rare item at level 13, and a very rare item at level 18.

Note: Blank choices are to help remind you. Select Done once you have chosen your item.

Done

Uncommon Magic Item, Done

Done

Uncommon Magic Item, Done

Done

Rare Magic Item, Done

Done

Very Rare Magic Item, Done

Never Did Know My Grandma

At level 10, you convince yourself that you must be something special. Maybe you're part dragon! Or part rust monster! Choose one of the following benefits:

• You gain proficiency in one saving throw and two skills.
• Your artisan's tools deal an extra 5d4 damage, and you can use "Commoner Combo!" 2 additional times per rest.
• One ability score is no longer capped at 10, and becomes 19 instead!

Ability Score Boost

One ability score is no longer capped at 10, and becomes 19 instead!

Proficiency

You gain proficiency in one saving throw and two skills. (D&D Beyond doesn't properly add saving throws, so just add the proficiency manually for now.)

Tools Upgrade 1

Your artisan's tools deal an extra 5d4 damage, and you can use "Commoner Combo!" 2 additional times per rest.

Didn't Know Grandpa Either

At level 15, you can pick another benefit from "Never Did Know My Grandma". You can choose the same one twice.

Ability Score Boost

One ability score is no longer capped at 10, and becomes 19 instead!

Proficiency

You gain proficiency in one saving throw and two skills. (D&D Beyond doesn't properly add saving throws, so just add the proficiency manually for now.)

Tools Upgrade 1

Your artisan's tools deal an extra 5d4 damage, and you can use "Commoner Combo!" 2 additional times per rest.

Tools Upgrade 2

Your artisan's tools deal an extra 5d4 damage, and you can use "Commoner Combo!" 2 additional times per rest.

Not Worth Your Time, Milord

At level 14, you have mastered the art of avoiding the gaze of the great and powerful. When an enemy targets you (and only you), roll a d4. On a 1 or 2, it resolves as normal. On a 3, it targets one of your allies instead, if possible. On a 4, it stares at you in confusion, wondering how a commoner got this far.

Not So Common After All

At level 17, you've managed to master your artisan's tools, despite all this adventuring! They add a +3 bonus to all attack, damage, and crafting rolls made with them, and you have world class skill in their use. Your DM will tell you what you can do with that, because crafting rules are too spooky for print!

Level 17

Here are the bonuses

Whew, Take a Breather Champ

At level 19, you have a crippling existential crisis as you ponder what it means to be a 19th level commoner.

Big Damn Heroes, Sir

At level 20, you can have up to 8 Questgiver quests active at once.

Limitations/Rules

Some of your class features will show up early, but this because of the limitations D&D Beyond put on the levels of subclasses. You should only get the bonuses once you select the feature when you are the appropriate level. I put this class inside of the Wizard since it has the easiest ignored skills for the Commoner and fits the proficiencies well.

• Please set all of your ability scores are 10 and keep in mind that they can only be increased by magic and feats. (this includes racial bonuses.)
• You get no background (Except for a Commoner background I am working on that will fix some missing things)
• Please Ignore any wizard class features and choices as well. You get no spells. Feel free to rename any wizard actions or features to keep them out of your way. (I put them as Z so they go to the bottom of the list)
• Please remove your Intelligence and Wisdom saving throw proficiency (you can click on them in your character sheet.)  You also need to ignore proficiency in Darts and Light Crossbows, although honestly that one isn't a big deal.
• Do not take starter equipment from the Wizard class (again my background will include the correct gear)

Note: D&D Beyond is okay with you never making choices on any race or class feature forever. Some of these limitations as well as some bugs require you to do a few things sometimes, so pay attention to each feature and follow the guidelines if you can.