I love AD so maybe I can add.

Ashe is played a lot for a few reasons. She's cheap to get. She's one of the better choices (by one of i mean you aren't hurting the team if you pick her cause shes in the top 5-6 best AD). Her abilities are really simple (to a degree). Basically, your fighting is 3 things: q, w, and r. when you fight a champ, toggle q. When you're done, toggle it off. W is a great slow, but shouldn't be spammed. Damage scales ok on it and can hit a whole team. The only thing with R is its a skill shot, and should be used from outside the enemy teams vision because its easy to dodge plus farther distance = longer stun. When you use it, its to initiate a teamfight, lock someone next to a turret, or "FUCK I WON"T SURIVE, RUN!".The hardest part of Ashe is using E properly, but that doesn't affect a teamfight, so it shouldn't hurt your problem. I started with Ashe and still play best with her.

Tristana is pretty nice to learn because she scales damage well and her skills are pretty straight forwards aka not too much thinking and aren't hurt too much if you don't do them in the right order.

A lot of people have said Graves so I will include him, but not describe him.

Other than that, most of the others have tricks that you need to know or important skills.

The important thing about ADs is you don't really need to rely on the abilities. Theyre AD! So AA is king most of the time.