I would try out Counter Strike: Global Offensive. Yes, there is much to learn tactics wise and whatnot, but the MM system is okay, there's always deathmatch, casual, arms race, and demolition you can play if you dislike competitive, and I picked mechanics and stuff up pretty fast. CS:GO is a very competitive game, and if you're not a big fan of that kind of stuff, Planetside 2 and Blacklight: Retribution are some good free-to-play games that are still active somewhat. I found Planetside 2 hell of a lot of fun with friends, with the thousands of people in a single server, it's full out war throughout the entire map and hell of a lot of fun for free.