You cannot get 400 spins right away after installing the game and playing for 5-7 days. But, regardless of the details, you can get a lot more than 400 spins if you play the game for long enough. You can also follow specific common methods that are given below.
Share spins with your friends back and forth every day
Try completing card sets (especially the Circus set if possible)
Invite new friends to Coin Master
Participate in various events
Take part in the giveaways that are held on the social media page of Coin Master
Follow these steps, and you should be able to get lots of free spins in the Coin Master game. Consequently, it won’t be long before you will have 400 spins at your disposal.