Go to the account application, fill out the form, click on Submit, and your application will be delivered at the speed of light to the moderator's Inbox.
Soon, the moderator will open the Inbox and then spend at least 10 seconds looking it over, and you'll be notified by email when it's approved, along with login credentials. If that doesn't happen within the time your patience (or eagerness) allows then go to the MAOA Support System, open a new ticket and ask something like "What's the status of my registration application?" Please be patient. The support people are volunteers, dedicated to helping you promptly, if possible. (They are also trying to build, fly and/or maintain airplanes.)