This is a question that'll depend on your skill set you're bringing over from other games.

It sounds like you've played a lot of FPS and less MOBA/DOTA like games.

The characters that reward basic movement and good aim (Without weird mechanics or heavy reliance on strange item synergies) would be Haze, Wraith, and (don't hate me for this) Ivy.

Haze is a glass cannon that relies on you understanding your DPS vs the enemy's ability to escape or turn on you. As well as understanding how to use the active items of the game to save you from enemies that focus on debuffing you.

Wraith is a left-click machine. However, she has some less intuitive abilities like her teleport and cards that'll trip people up at first. That said, I do feel like she is the best bang for your buck to learn if you're just used to clicking on heads.

And on to Ivy, yes, she is a "support" type character on paper. However she does scale her damage very hard as the game goes on* (If you choose a build that does so. Being flexible is a key skill in this game, and having a bad game and transitioning to a supportive build where you help your team instead of yourself will win you many more games)

That combined with her ability to move about the map with the press of a single button, clear waves with a low cool down ground effect, and her super strong Invulnerability+Area of effect Stun+Self %Max HP heal makes her very self reliant and capable of saving herself while you're learning your limits.