If you're using BuddyPress, then that url is the correct url. You'll simply want to replace yoursite.com with your own site's domain name.
If you're using WordPress, the signup page would be yoursite.com/wp-signup.php.
Hope that helps!
I installed BuddyPress, Activated it, used the URL for registration using quieroquesepas.us in place of yoursite.com and it still just redirects to the home page.