Intro Offers are a great opportunity to let your customers try out your services.
When creating a subscription, just below the Duration Settings section you'll find the Intro Offer toggle. If you opt to use this, the subscription cannot be an auto-renewing subscription.
Pro tip: when a customer's intro offer is expiring, invite them to purchase a subscription or pack that gives access to those same services. You can even automate this messaging using Sequences to Target Intro Offer Customers.