When you create a new account you can select a plan to get a 14-day free trial to try out the app before you get billed.
You'll have full access to everything in the plan you selected.
After the 14 day trial, the credit card you entered will get billed for the plan you selected.
I've you've tried the app and decided it isn't for you then you can cancel your subscription before the 14 days are up and you'll not get billed.