Titan fall takes a bit of getting used to. Gameplay is like Quake mixed with halo and cod :D
Once you get your head round how the game plays its a pretty good novel FPS.
Basically there is no single player, after the training it's straight into multiplayer playing through the campain. You'll play the missions in order if you play from start to finish. If you leave the game, the next time you play will be a random mission on either side. Then you will play out that story line in order. So you could start the last mission on either side as your1st game, sit through the credits and then play mission 1 again. After you have played both story lines through you'll have completed the game. Then it's just replaying the missions or the different mp matches ala cod, halo and all the rest. It can take some time to complete both story arcs as you get booted back to main menu every now and then.
Pretty sure gambit would be willing to dust it off if you want to get together for a game of TF.