Stop asking questions and start reading!
Domain is the name of the site. yoursite.com is a domain.
Registrar is the place where you get your domain - godaddy is a registrar.
Host is where your site is physically hosted, meaning where your files are.
And no, you can't get a free domain or be your own registrar. Actually, forget all about free for now, you claim you want to make $50 daily, yet you seem to be obsessed with trying to save $10. That's not a good start.
You need to choose your domain name, register it at your registrar and host it at your host. Use google or the search option here to see which registrars and hosts people are recommending.