In "Tasks and Events” in the main menu you can always find a number of tasks that are available for you.By completing these tasks you can earn extra Credits and Coins.

These tasks typically ask you to perform actions you're already doing during regular gameplay. 
Some tasks require you to complete other tasks first. Most tasks reward you with Credits, but there are also tasks that offer Coins.

New tasks appear daily, with special tasks available on weekends, and additional tasks often added during special events or when new content is released. Premium players also have access to exclusive tasks.

Once you've completed a task, don’t forget to claim your reward.