You have owned the bike for 18 years and its still running, so you must be doing something right.
If you want to start working on the bike yourself, I would start with things like oil changes, spark plugs, air filters... and as you get your confidence up you can pull the wheels off the bike to take them to a shop to get the tires changed, and save about $70 for the pair.
If you dont have one, the first thing you should get is a torque wrench. EDIT: 3/8" drive will cover just about everything. The one thing you can do to these fine machines and create a real nightmare is to overtighten a bolt into any part that is aluminum and strip it out. The torque wrench will keep you from doing that.
A handfull of sockets, and a few allen driver bits, and you can do all the things I mentioned by yourself.
Last edited by KCW; 04-12-2018 at 08:20 PM.