>what to roll for
Use whatever recommended on the wiki.

>how to reroll
Literally tap red button to redraw gacha.

>how to bind an account
Game option > account transfer
Might want to include translated option menu pic.

>how to restart a new one without deleting the old one
Bind account, then clear app data through android menu.

>how to add friends
Use character as guest, then press right button to request friend.
Search for player ID from friend menu (again, translated option menu).

>how to setup support
group > support group.

>how to change favorite kirara
pomf her into your bed.

Might as well add how to equip a weapon.