Yeah, it takes a while. I have 15 mains now, but that took months to get really good with them all. For now i'd say focus on Mario and Marth and then branch out to other characters. You'll improve faster like that~
I hope this helps!
I'd say like maybe 2-3 days a week. It's what i usually did. but now with work and other stuff I haven't been able to play much lol. Now I'm rusty again.
and yess Jedi. we got to play again =D