How should I go about making animated characters and what programs/tools should I use for it?

So I have a pretty good fleshed out idea for a 2d platformer game and I finally want to see it in action but I don’t exactly know how to go about doing that seeing as rarely (And I do mean RARELY) use the unreal engine. But regardless I still want to try however I Immediately came to my first wall, I have plenty of drawn characters but how do I get them into unreal and to give the character movement?

Also I’ve heard that photoshop is somewhat necessary to the whole animating process but I don’t exactly have money so is there another option? Or a different program?