Beginner's Protection lasts for 7 days (168 hours) from the moment your account is created. You will not be able to pause the countdown after it starts, even if you do not access the game within that timeframe.
 

Upgrading your Keep to Level 5 will immediately end your protection, even if the seven days have not passed. However, attacking a Wild will not break your Protection.

Tip: Make good use of your first seven days to develop your city, train troops, and prepare your defenses before entering the battlefield!