Subdomain to Domain?

Hey guys, I have a question if you got a minute to help me. I was just curious I never have bought a domain before. I have a subdomain self hosted blog I run at 000space.com. I like the server an all but it is a tad bit slow. I was thinking if I started to pay for one of their plans that comes with a free .COM, .NET, .ORG, .BIZ. .US, .EU, or .INFO. That it would improve my speed and also allow me to now have a domain right? so if my address is http://www.o900lbGorillao.000space.com. Let’s say o900lbGorillao is available and I get the free .COM I would have o900lbGorillao.com? Correct? Also if I change my plan to a paid plan instead of free. What kind of setup does this require? Do I have to move anything in Cpanel or with FTP? From what I see the plan would probably just change over from Free to there 7 dollar Ultimate one, which has unlimited bandwidth. I am also helping it improves the speed to the site which I don’t know if it would. Since from what I understand I get 205GB free bandwidth an if it gets used up you can no longer view the site till next day.

But going from a sub domain to domain.com worries me how much I’d need to do or know before hand. I have never done it before.

If anyone can answer some of my questions I’d really appreciate it thanks!