I don’t think there are online multiplayer games like CoD or CS that don’t require a platform like steam or good old games to buy, download, and run. I’m not actually sure what you’re trying to do, but if avoiding marketing is your goal I recommend you run steam and change the default page it opens to to be the library where your games are and not the store
People are attracted to people who are comfortable with themselves. Take the time to learn who you are, and friendships, romance, and relationships will follow.