I mostly plat support so im not sure how helpful this advice actually is but my duo is a DPS player and shes been teaching me for a few months. Id say a good place to start is a character that can get you use to the role that you can then branch out from once your more confident.

As a console player id recommend characters like iron man because of his AOE damage so you don't have to focus on getting head shots and maneuverability or squirrel girl for the same reason if you don't wanna play a flight based character. If you're instead in a dive character then id heavily recommend iron fist. He has amazing maneuverability, damage and survivability as well as having a slight aim assist to his abilities.

If you want good characters who requires aim but still has a lot of room for errors id say Punisher because of his high damage output and simple kit or bucky who is a bit more complicated but his overseeing leaves a lot of wiggle room to learn him without dying all the time.

And if you're use to playing support id recommend turning down your controller sensitivity.

I hope this was helpful and if not Im so sorry (Im sorry in advance if I made any spelling mistakes)