When you create your account, you get 7 days to explore Ads Editor. During this time you can get to know the manager, connect your accounts and try the features. To keep using it after 7 days, just choose a plan in My Subscription. In flows that ask for a card when you sign up for the trial, the first charge only happens on day 8, and you can cancel before then without being charged. If the trial ends without an active plan, access to features is blocked until you subscribe.