What heroes and teams should I invest

I playing game about 2 weeks and can't figure out what to do.

I wanna play heroes that I like vissually like yasmine, cascade, cornelius or heidi. but soul stones of them is kinda hard to obtain and I don't really know who to team build in this game.

I have some well upgraded for my lvl charakters like oya, mushy, folio and some I guess useful like polaris, sebastian and tempus but their only 1 star.

help me with yall advice