Correct. You want to start from the bottom and work up. Each tier helps you get a solid start on the next.Juggernaut is the best at clearing the 1* node in DDQ, but Iron Man or Spider-Man can do it just fine if you like them better. Then, yes, start filling in the rest of the 2* that you don't have. The Champion rewards from them will give you (among other things) Hero Points to pick up more Roster slots so you can really get to work on the 3*.Of your 4* with fewer than three covers, only Luke Cage and Jean Grey stand out as characters I would really want to keep. And even they could go if you need the space, but even keeping those two, that gives you more than enough room for the rest of the 2*. You may also want to sell off your 5* Characters, especially if you want to play much PvP. Their higher match damage will be a big help in PvE, tho, and they'll be hard to get back when you do get that far, so I don't know that I'd recommend that, but it is an option.Doctor Strange, Thanos, and IM40 are the big three of the 3* tier. Focus on finishing and champing Strange and Thanos first. Patch, Daken, or Rocket & Groot are all good to have along with Thanos, since they can heal from the team damage he causes, and Patch also works amazingly together with Strange and Iron Man to take on nodes without tile-movers.None of the 3* you're missing are particularly amazing, you've got all the really good ones at least Rostered. Bullseye, Spider-Man, and Star Lord are the only ones I might prioritize, but mostly just go for whoever the Sneak Peak thread says is going to be Featured soon, whether in PvE, PvP, or Deadpool's Daily Quest.A note on resources:ISO: I don't think there are any other things to do with it any more, but if there are, don't spend it on anything other than leveling Characters. Focus it on Characters who you can Champ soon.Hero Points: Don't spend them on anything other than Roster slots. Eventually, you'll get a surplus and you can start using Shields in PvP and buying extra Tokens and stuff, but for now, none of that is worth as much as more Roster space.Command Points/Legendary Tokens: Don't spend/open them at this point. Just pretend they don't exist until you have all the 2* and 3* Characters at least Rostered, and most of the 3* Champed.I hope this helps some. Welcome back, and have fun!