Will I be charged for the days of the trial period that I do not use?
No. You will not be charged for the first 30 days even if you enter your payment info before the trial period is over.
Once you enter a payment method, an invoice will be created and debited from your credit card immediately. However, the beginning of the billing period starts after the trial phase.
For example, if you register an account on the 1st of July the earliest date of the billing period is the 31st of July.