How should i be playing this game, or building characters or my account?

I haven't played this game much, i just got yuzuha the red girl and started the game again for her.
I sorta skipped the story and got to chapter 5 mainly to get rolls plus i can't do any of the events because it's locked behind the story.

I'm proxy level 36 btw, i can't farm the discs as i can't guarantee Srank drops so i hit like shit, and even farming hte level up materials takes ages.

I also don't ge the bangboo thing, what's the best one to get? Does it matter?
I also mainly use corrin, vivian, nekomata and soukaku and swap between them. I don't know ho wot build teams.
What should i be doing fgor my account?