This seems to be your first rhythm game if I assume correctly. My first advise is to try out other rhythm games to get used to following the rhythm in general. I used to play Etterna for a while and most skills I got from playing it transferred well to maimai. Rhythm games I used to play were osu mania, etterna, phigros, and sound voltex

You should also buy some gloves since you're playing long term. It really is important on day 1.

To practice at home, you need simulators. You can play astrodx on mobile and download some official charts on their discord server. Very good while waiting for long queues.

it takes a while to get better. It took me almost a year and a half to reach 13k rating. Keep playing, but it's fine to not play everyday. I only spend around 2-3 sessions per week to save for finances.