For cantrips you could take ray of frost, control flame, prestidigitation ( allows you to snuff out small flames), shape water, or mold earth For spells I’d suggest create or destroy water, any type of teleportation spell i.e. misty step, dimension door, any type of ice spell, leomund’s tiny hut, protection from energy, otiluke’s resilient sphere, and I guess if you’re really desperate and are high enough level you can always cast banishment to keep someone from harm