We share one email address. How does this impact account setup on this website?

You can only have one account per email address.  So only one of you will be able to have a website account to access course resources.

This won't be a problem during registration if you register together.  You can register more than one person and only the main person registering has to provide the email address.  If you register while logged in, it's even easier.  All your contact info will pre-fill.