How do I see the members who have signed up?
And how do I edit the footer to add my brand name and copyright (not removing Vanilla branding)?
For your memberlist, you can see it as an administrator in your dashboard, under "Moderation". If you want to add a public memberlist to your forum, you can use plugins such as this one:
And about your own branding, you can create your own theme (based of the default if you wish). I suggest you to read the documentation:
The is a user list in dashboard
Check out the Pockets plugin/widget