You can set up a Free Plan to invite one or more members to a Paid Mighty Network or any Plan for free.
To do this, create a Free Plan and mark it as Hidden. Start by watching this video tutorial and/or follow the instructions for creating a Plan.
Please note that members on the Free Plan will be sent a $0 auto-renew notices from Stripe. To avoid having this notice sent out, you can pause your payments for your $0 plan in Stripe. This will save your $0 charge as a draft in Stripe, but not send out the charge.