Steps:
Create new subscription and add the product to the subscription and set the price.
Create a renewal order.
Change the price of that renewal order to $0 (this will activate the subscription so you don't have to wait until they make their first payment to set the end date).
Go back to the subscription and create another renewal order for the first month (this one you'll send to the customer for them to pay).
Go back to the subscription and change the next renewal date to be 1 month from today.
On the subscription, click cancel and then choose the date (1 month after the last payment they need to make).