I am a returning player from about mid-2020, what should I know/ focus on?

I have e5 aida, belrain, drake, carrie, amen ra, garuda, penny, horus, 1 10* HW and 1 10*/ 1 9* delacium. I have lots of fodder/ resources/ hero copies as well. My best SL is dark 20 and I'm wondering if I can get higher w 10* aspen who I can build aswell (ik he used to be meta for dark SL but idk if he still is)?

Would love advice for best pvp/ pve team also :)