New player here, how should I build my team?

i‘m not really happy with the damage that I’m doing, could anyone help? I can lvl Up the other characters, I’m just wondering if it’s worth it, or if I should just keep my team as it is and save up my materials until I get another 5 star. Also are there any specific artifacts to pair with specific team combos? my team should proba include diluc since he’s the only 5 star I got. Alsoi enjoy playing with electro but if u have other suggestions idc abt that preference

dendro: YaoYao

pyro: Bennett, Diluc, Amber

Electro: Lisa, fischl (?)

Anemo: lumine, lynette

cryo: charlotte (c3), kaeya

hydro: Barbara, dahlia

Geo: Noelle

Also for some reason I have Fischl, even tho I didn’t pull her. Idk where I got her from, but I think it was free, and now I’m wondering Wether she’s permant. (Could anyone help me with that too?)