Oh, that looks like you’re in good shape to move forward, but there’s some foundational stuff to focus on first. The overall strategy for a roster is to build it up from the bottom, excluding 1stars. I’ll explain why, and I’ll just assume you don’t remember anything.
So, covers are levels. Each character can store 13 covers, and their possible level goes up with each cover added, until you hit the max number of covers, which all have to be in the correct power distribution. So, say you’re working on someone who has red/green/blue powers, and you have 5 red covers, 3 green covers, and 2 blue ones. Any additional red cover you try to apply is just going to get saved because you can’t go over 5. Saved for what? Well, after you max out powers (with covers) and levels (with purple ISO) then a new button appears to “champion” a character. This allows you to change power levels whenever you want, and every additional cover you get is a reward, from more ISO to Command Points (used to buy premium token pulls, mostly), to Hero Points (the ones used to buy roster slots) and more, like covers for higher tiered characters. Champ levels are your bread and butter for resource acquisition, they speed up your progress a lot.
Here’s the issue: you don’t have any 2-star characters rostered. That’s the first thing I would work on. They’re the most common kind of cover, the most plentiful rewards, so you definitely want them. They’re also required for some events, like the Deadpool Daily has two nodes that are 2-star and below only, and the harder node has a specific 2-3-4 combo. So definitely roster and champ all of them first before focusing on anyone else. It looks like you’ve got some max champed 3s too, so you’ll want to maybe roster a double to start earning rewards again. Depends how bad your HP situation is, but it should be pretty good cause you have a fairly strong roster and can compete in higher level events.
[Medusa/Nico], Gamora, and 4* Rocket and Groot are a good team, though meta has moved on a little bit they’d still be able to clear SCL 8, maybe 9 (I actually don’t know how hard 9 is, so give it a shot maybe?) SCL10 is endgame content, very difficult, so you might have a rough time. I personally just finished my 3star champs and I’m working on leveling up my 4s, so I’m behind you.
Other good team combos off the top of my head are [Medusa/Doc Ock/Carnage], [C4rol/Coulson/R4G] - Wasp is a good fit here for R4G if you get her covered.
So yeah, make sure you’re not wasting any rewards from 2 or 3 star covers, and set your favorite characters. Shards replaced bonus heroes, which you might remember. Shards are basically pieces of a colorless cover, so when you get to 300 for a 3, 400 for a 4, 500 for a 5, you can just buy a power outright. Really helps when you have a bad cover distribution and you need to fix it. In the worst case you can get 5 of two colors and have 0 of the third. Every time you get that specific character (which the odds are pretty low of randomly pulling a specific character, especially 4 stars) there’s a 66% chance you won’t be able to use it until they’re champed.
I’d set Kitty as your 5-star target, for 4, make it the 4star Juggernaut, and for 3, Magneto cause he’ll earn shards for Juggernaut. Or you could pick 3star heroes that are close to an HP reward cause you might need some.
Looking forward you’re going to want to roster all the 4s and work on covering and champing them. Let me know if you have more questions!