Redirect (or log in) users after registration

I’m setting up a free file page, but I’d like users to register as users on my site before getting the free file. I was able to set up a login redirect using Theme My Login– but no registration redirect.

Is there a way I could redirect a user after registering? Or, even better, could I somehow automatically log a user in after registering, so that the login-redirect of Theme My Login would take over?

Thank you