To view your subscription's renewal date, you'll first need to open your Account page. You can do so via clicking this link, or clicking your Profile in the top right, then clicking Manage Account:
(Note you may be prompted to sign in once more)
Once on your Account page, navigate to My Licenses in the lefthand column. Under My Licenses, you will see your subscription status with your end date and payment method. If you are using the free trial, your status will show "Trialing."
Once you reach the end of your validity date, you will be charged at the monthly/annual rate depending on your subscription plan.