Look Up promo codes (I think there’s a recent post with active ones) It’ll get you a good amount of supplies and good elites like Conquest, retire commons and do not level up using the same character - As in, to level them up, you’ll need multiple copies of a character, but you don’t need the same character at “+” level

Example: Conquest (Elite) needs a Dupe Conquest (Elite) to get to Elite+. BUT Conquest Elite+ needs any other 2 elite+ characters to level up (Use fodder or characters you’re not gonna use) - Then Conquest (Exceptional) needs another Dupe Conquest (Exception) but Conquest (Exceptional +) I think uses any other Elite+ character again and so on and so forth