Hi dfpcmaia,
Welcome to the QuickBooks Community. I'll be answering your question about direct deposit.
The invitation email contains a link that will let you create a QuickBooks Self-Employed account so you can enter your contractor information. Your contractor data will then sync to your profile in their QuickBooks Online account. You don't need to sign up for a trial account yourself. Just provide your W9 form and bank details to your contractor via email or in person, and they can enter the information into QuickBooks.
If you have other concern, feel free to go back to this thread. Take care and have a great day!