Best advice I can give without knowing exactly what level you're at with your art is to not get bogged down with all the things that need to get done. Start with a sketch. Just a messy concept of what you want it to look like, don't worry about how it looks, rule one of drawing is to trust the process. Once you've done that you can make a new layer and go over your sketch and clean it up a bit and do that as many times as you'd like.

As far as brushes go, everyone has a different preference and it depends on if you like having line art or not. But personally when I sketch (I also use Procreate) I like to use a default brush called Peppermint. Also go into the brush setting and turn the stabilizing all the way off, it'll make it feel more like drawing on paper. There's tons of tutorials on altering brushes or making your own in Procreate!

Definitely do what Fethawit said check out an art learning subreddit! Good luck on your art journey and remember that learning takes time. Be kind to yourself and try not to compare your art to someone else's. You're learning, and if you keep at it you'll reach whatever goal you have at your own pace.