Make something every day. Spend 1-2 hours tops. Learn the process of going from start to finish, not spending too much time on details. You can follow a tutorial for your daily project. Try out as many different looking styles as you can. Don't stick to 1 kind of aesthetic. Over time you'll learn a bunch of different techniques and styles that you can blend together to create your own style or make anything the way you want it to look. If you did this for even 6 months straight, you'd probably be able to start getting paid for it. Keep an inspiration moodboard on Pinterest or Instagram to get a good idea of what high level design looks like.