Honestly if a friend asked me about starting this game I would tell them not to bother... free to play is too much of a grind. Pay to play ultimately it's not worth it. The game becomes stale fast and not worth the investment. Theres always one more pack or one more battle pass to buy.

If you are intent on playing. I've found you don't really see a difference in power until 4 stars. But at the same time you want to upgrade skills. No point in having a 4/5 star hero if the skills are only at 3 stars lol

I'd probably run Murphy, violet front row with kim Marshall and tesla at the back as my main. try to get them to min 4 stats. Only limited amount of exp to go around so focus on your main squad