If you don’t want to spend money, then get IBIS Paint. It’s free, beginner friendly, and had everything needed. I’ve seen people make pieces with IBIS that make my best pieces look like a kids doodle. Only con are the ads you have to watch to use certain brushes. Not every brush has ads.

If you want to spend money, get Procreate. It’s literally just IBIS’ big brother. Tons of options, brushes, and other stuff but all extremely simple to look at and use. Procreate will help you tons, and doesnt really have a downside to it.

I use Clip Studio Paint for my main works, as I believe it’s the best and most professional program. It has typically better brushes for my artsyle, plus everything Procreate has but better. CSP even has a website just like this one for uploading and downloading brushes/3D models. Yes, CSP even has 3D models that are completely articulate and poseable that you can use as guidelines. Only con, it’s a subscription based program, but only like $5 a month.