well the easiest method to do input in unreal right now is the enhanced input.
yes, it has some weird terminology and you have to have some fundamental understanding of some programming concepts for it to make sense, and that can take some hours to get a handle on… but, there is tons of video tutorials explaining it all. you can take your pick like a buffet - if one author has a voice that annoys you, find another, lol.
that is easiest because epic has made a lot of things like what you want to do just a few parameters you can turn on or off. So just a ton less code you’ll have to write.
In general, game programming is always a much bigger PITA than you’d expect it to be, so just get used to that.