Ditch the PC - go and get a top-spec Mac laptop with a fast external HD (for regular backups) - I'm not being snooty about the Mac thing, it's just that: Macs are made 4 creative people, they're very (instinctually) intuitive, u can run the whole adobe suite on it but with Mac u have a MASSIVE advantage with FINAL CUT. It is as close to a professional studio u can get for a couple of thousand (tops).
Macs are still way ahead of PC with regards multimedia creation. PCs are still basically number-crunchers. Sure, puts good graphics card in anything you'll get good-looking graphics for gaming, but Macs really are built and designed with artists in mind.
Make regular backups, and try to start each project as near the start as you reasonably can, then build clips on top of each other from there - remember, the bigger the file you have the less memory your computer has to work with, so it'll get slower.
Start off trying out skills and learning keyboard shortcuts - try a music video first.