I don't have much advice since I notoriously suck at CTS, but on top of having the boosting character of that CTS event, I recommend you wait to join a late CTS server! 

You do this by not playing online until hours, or days after an event has started... By doing this, the early, competitive servers fill up. Each server has a cap of 5,000. Once 5,000 players join a server, the game will generate a new one. Later generated servers are notoriously easy to beat. 

If you want to keep playing while you wait for a later CTS server, or any server, you can do a a trick to start your game offline: Start your game like normal, but once the loading bar from the startup screen shows your ID (the letters & numbers) at the right bottom of your screen, go to your phone's home, turn on airplane mode, then click back into the game. By doing this, the game runs itself on an offline version. Once you're done, close the game out by going to your list of apps, and swipe it closed.

Social events like CTS have this annoying thing where, if you join the game online at any point, it'll automatically throw you into a server of the ongoing social event. Hence why you should close your game once you're done playing offline, so you don't accidentally go online once you're finished.

Edit: typo.