On my site, I only have two membership levels. "Visitor" and "Members". So, once you register, a message appears as shown in the screenshot:
You currently have a subscription for the Members subscription. If you wish to sign up a different subscription then you can do below.
Well, unfortunately there are no other memberships to choose from because I haven't defined any! Is there a way to prevent this? Come to think of it, I have a "Welcome" page defined, so how can I make that page display immediately when registration is complete?