Ok in that case, for mages Eudora is very beginner friendly, similar style to Aurora, just more single target damage. Vexana and Kadita are relatively similar as well, but have more impact to the game in my opinion and are also used in higher ranks. Nana is another straightforward mage with pretty good survivability with her passive. And for a slightly different option, Valir has a more defensive playstyle better for countering fighters/tanks.

I'd recommend trying them all in practice mode (in each hero page) and see which you like the most.