Your best route towards a fighting game is to search for “UE4 beginner tutorial” on YouTube and work your way up. I suppose you can watch the tutorial that @BreakMaker linked but I suspect you will run into things you can’t make sense of.
Most people who go that route end up coming back here and asking us question after question as they run into problems in their tutorials. That’s no way to learn anything. And it makes our lives harder because any answer we give won’t be understood so we end up writing it for them. Again, no learning. And that means they’ll always depend on others.
What you want to do is plan your route so you are making fun things as you work towards a fighting game. So maybe since a fighting game has jumping in it, you try some third person tutorials and then try some jump tutorials. Fighting games require collision detection so you could learn about collision/overlap in general first. The more you learn the more you’ll know where you need to go next.
Good luck and remember: there’s no shortcut to mastery. That’s why there are so few masters.