True adults don't have to mention that they are adults.Remember when you thought 21 was old?
Blunt - seems like you have forgotten what it is like to be 21!
Jdsfighter - I do agree that based on the information available it may have perhaps been wiser to avoid this bike and buy a newer and less abused bike.
However, any vehicle is much like a large mecanno / Lego set with a little electrics thrown in. Most people can build Lego sets (even one with batteries and motors), so if have a manual, a few tools and (if you are lucky a few knowledgeable friends) there is no reason why this bike cannot be a great learning curve for you.
Like many I was taught to rebuild engines by my father helping him first to repair/rebuild his cars and then my motorbikes. Trial and error has also proved a frustrating and ultimately informative method of learning (and remembering). The sense of satisfaction in the achievement is also worthwhile.
As the saying goes (or at least something along these lines)
"Necessity is the mother of invention"
Or in this case the cause of learning to do it yourself.
My advice would be:
1) Take a good hard look at the bike and work out what it needs (or is likely to need) to finish to the standard you want
2) Value the parts (and time - if you are learning estimate the time for a professional and treble it, then add some for figuring stuff out, getting tools etc)
3) realistically value the bike as it stands (scrap, parting out, whatever)
4) then compare to what you can buy for that money
This should give you a good idea as to whether to sell it and buy another.
If it is still better to keep what you already have, that is the way to go (unless you can afford to put yourself on a bike that runs well now!).
If you continue to refurbish your bike - evilbay can be a good source of parts if you are prepared to wait for the right part (at a reasonable price)...