How much would a standard setup from GC cost? String change, fixing action, cleaning the fret, and also fixing up a loose output jack.

I know I should learn how to by myself, I'm not handy though ^.^

Just estimate please?
Friend just bought a Jackson from there.

$60 flat rate for "setup" covers all that junk you listed. But i still recommend doing it yourself.

Depends on the tech, but the guy at the store in Tacoma really blows... he has no idea how to work with a FR.
I know you said you are not handy, but I implore you to give it a shot. Learning how to do that kind of maintenance work is a really important and valuable skill. Moreover, it costs money and time to get that maintenance work done. Providing you have the tools, it is an easy job to do yourself.

Check out my blog, I occasionally write posts regarding maintenance work. E-mail me for specific help if you would like!
A blog dedicated to educating beginner's on guitar and music technology.
I guess my GC is better. I just called, they said they'd do it for free ^_^