Intro is a paid start, not a free trial: the €1 plus VAT is charged when you begin. During those days you can use everything in Business, including campaigns, polls, the CRM and webhooks.
To stop it from turning into the Business subscription you chose at the start (yearly unless you chose monthly), cancel before the first regular charge; you keep Business access until the end of the paid days and then move to the Free plan. You can also start directly on Free, Pro or Business.