I would suggest that you start by going through all the maintenance items, fluids, brakes, splines, filters, etc. A set of new tires at the start is a good idea because tires for these old bikes can be hard to find on the road. I had to buy a set in Colorado that cost me nearly $700 installed. Valve gaps, throttle bodies should be checked. A good inspection of the clutch and throttle cables. Install a new headlight bulb. I use cheap Volar organic brake pads, and change them every 10,000 miles. You get the idea.
If you don't have one already, find an OEM tank bag with the rain cover. I carry a flashlight, AAA maps, snacks, a first aid kit, spare eyeglasses, a magnifier to help my 72 year old eyes read the maps, a bottle of water, sunscreen and toilet paper(in a ziploc bag). If you take any medications, you might want to put them in the tank bag as well. A small bottle of BugSlide and a microfiber cloth fit in the bag to clean bugs off my windshield.
I carry some spares and a tire repair kit stashed around the bike. Stuff I carry is what I might break in a spill that could strand me. Clutch cable, throttle cable, clutch and brake levers, shifter, fuel pump, and a 12v compressor to inflate tires.
I also have some extra tools: A harbor freight 1/4" drive socket set and a couple extensions along with a set of ball end Allen wrenches and a 4 way screwdriver with big and small Phillips and flat bits. Sometimes I pack visegrips.
A good touring jacket and pants both with CE rated armor along with boots and socks. I usually wear a pair of cargo shorts and a t-shirt under my gear in the summer or down south. A good investment is a wet vest when you are riding west of the Mississippi. They really do keep your core temperature down but only work really well in dry heat. Good hearing protection will make riding all day a lot easier. I have found 3M Skull Skrews ear plugs to be very comfortable and they block out more noise than any other plugs I've tried. 1 or 2 pairs will easily last an entire trip.
I think my best idea is what I call a "rescue box". It's a USPS flat rate box packed with spares to fix almost any mechanical problem short of throwing a rod. Relays, monkey knutz, Hall Effect Sensors, starter, coil, plug wires, engine temperature sensor, and a fuel pressure regulator, etc., along with a multimeter. It's all packed and ready to be mailed by my wife to wherever I'm stuck. It saves me having to describe what I need and where it's stashed along with her having to pack it so it won't break.
My jacket has a secret pocket where I carry a stack of $100 bills for emergencies. My pants have a small pocket above the right knee where I carry my credit card for fuel, about 4-5 twenty dollar bills for stuff like food or tolls and a spare key. That saves fumbling with my wallet at fuel stops. My cheap flip phone goes in the same pocket on the left side.
Hope this helps.
