Welcome Logans,
There is so much here to sift through it's hard to know where to begin. The best thing I think I did was get a
manual. I found the Clymer KX manual to be great. It is cheaper than the FSM and will have everything you need to work on the bike.
http://www.amazon.com/Kawasaki-1982-1991-1983-2002-Clymer-Motorcycle/dp/0892878649/ref=sr_1_1?ie=UTF8&s=books&qid=1269574858&sr=1-1 These pop up on ebay somewhat less than new, as well as owners manual etc.
The next best advice I can think of is to verify the condition of the engine and Brakes!
A well tuned stock engine will give you a baseline to measure any future mods and may save frustration and $'s
Hopefully some of the guys with early bikes will be able to give you some options on parts availability and suppliers.
A word of caution on throttle control...
Don't be afraid to take it easy right off, things start to happen quickly, as I'm sure you'll find out.
Fuel/oil ratio, brands of fuel, pre-mix and tranny fluid have many and varied opinions. What type of riding you will do & skill level are things guys will factor in to their advice.
There may be other members in your area willing to help out.
Glad to have you along.
Tuck\o/