Quick question.. I just got the game, and I started playing Campaigns... after about 2 hours I am now level 7 but I have been wondering is Campaigns multiplayer? Because the names of these other players are so random and weird.

yes

Only the players on your team are human, or they can be if they join your game and play with you. Your opponents are bots. It's co-op, basically. To play full on multiplayer, you have to play the "freeplay" mode. Then you will play against human opponents as well.