Hi!! Mi wife is making a campaign for our friends but she as never dm before neither have i and im trying to help her out with random question about rules or what should i roll if i want to do this and so on. I was hoping if u guys could help me out with questions or anything to help her practice!! Thanks

There is a DM guide. That's a good place to start. That's going to have a lot more in it than a person can reasonably put on a forum thread.

DMing is all about preparation and improvisation. 

My suggestion: use the internet to steal everything you can rather than building things yourself.

Taking maps, town layouts, ect off the internet not only saves you the work of drawing things like this yourself, but also you can look at things on those items and write stories around them. This really helps flesh out a world.

Make the players do some work. Force them to write good back stories. Force them to have character depth. Force them to tell you about their interests and motivations.

These are foundational things that you can use. Take the player's ideas and incorporate them into your world.

This is how you get control over your PCs which otherwise can literally do anything. This gives them RP opportunities and makes the PCs feel like part of the world rather than just being in the world. And it gives you sessions upon sessions of content as the GM.

Yeah she have all that under control. What she need is more improv practice and thats what im trying to help her 

Quote from Wushii >>

Hi!! Mi wife is making a campaign for our friends but she as never dm before neither have i and im trying to help her out with random question about rules or what should i roll if i want to do this and so on. I was hoping if u guys could help me out with questions or anything to help her practice!! Thanks

I recommend running several very short one shots with you as the only player. The best way to get experience in my opinion is to just do it.

As for ideas on very short one shots, you could do something like finding someone's missing pet, taking the village's children out for a field trip to a nearby farm or library, help the town guards go on patrol and maybe beat up some criminals, etc.

Before COVID, one of my players tried GMing with me as the only player, and I thought the one shot was pretty well done, and it was all improv. The overall plot was that a giant stirge kidnapped a person's baby and my fledgling adventurer tried to save and return the baby. Despite events going horribly wrong and things got pretty dark, I think the one shot is pretty good overall. 

Improv ability is something that you can only develop over time. She is going to be very shaky at it to start, because we all are. I have GMed many times before, though I hadn't for a long time, and now back into 5e for a year coming up in a few weeks... and I still suck at improv. Some people are just wired for it more so than others... but I have gotten better at it over time.