Replace all fluids, check for leaks from all fluid systems, check for any chafing of the electrical harness. You could disconnect all wiring connections to see if you have any corroded connectors, and it's not unusual that somewhere or another you'll find a connector which has corrosion at the crimp or where multiple strands are broken. That last one might be hidden inside the insulation, you might notice one connector has a 'loose' feeling to it because of broken strands compared to another which has a more 'solid',' connected feel. Sometimes the spade terminals need a bit of a burnishing to remove light oxidation, or sanding to remove corrosion, or even replacement if the terminal(s) is (are) rotten. Use dielectric grease when re-connecting everything and make-sure the connections are well-insulated and the wire runs are correct, not chafing, or not stretched. Consult the online service manuals in the electrical section. A squeeze to tighten the female terminals may be needed if they are loose upon disconnection.
Really, you just need to ride the thing, and its needs should become apparent quickly. From a safety standpoint, I would go through the braking systems from the right handlebar to the calipers, and the right pedal to the rear caliper. The fluid should be water-clear once it's flushed, and you might want to flush it a couple times if you don't choose to dis-assemble the systems. A set of new HH pads is a cheap investment, despite the linings you got w/it have plenty of wear left. If they got oily because of a leaking fork seal, or worn to where they scratched the rotor from not being replaced in-time, you may be in-need of a rotor as-well. Rarely will you need to replace a caliper, you can usually dis-assemble them, remove corrosion, and re-use the same seals, unless you have a swollen seal, that is usually seen w/the dust seals when corrosion on the piston(s) causes a long-term leak, ignored. Use a light film of clean brake fluid on the square pressure seals, and on the piston sides. You should be able to finger-press the pistons back-into the caliper bodies when they're clean if you dis-assemble/re-assemble them.
Make sure the shocks and forks still have damping/rebound, chips in the shafts passing the front or rear seals means replacement time for the downtubes or shocks.
For me, the biggest bang for the buck is going to radial tires, which will require a new or used larger-diameter rear wheel, the front wheel can take a narrow 18" high-profile aspect-ratio tire. You will see a greatly-increased handling function, less wandering/weaving, and more-precise steering. You don't need $2200 wheels to do it, though some guys like the best you can get.
If your steering head bearings aren't 'notchy' when you jack the front wheel off the ground and move it from stop to stop, you may get-away w/an adjustment of the bearing tension. Dis-assembling the front end & changing oil and possibly RICOR's or Gold Valves and Race-Tech or Progressive Suspension springs, and new oil will make you happy you did, after you compare how it will work to how it did work.
If the clutch slips, bite the bullet and get the "extra friction disc" OEM friction discs, and the heavy-duty diaphragm spring PCW sells. Forget the DD (Double Diaphragm springs) unless you were unnaturally attracted to those cheesy "Bullworker" exercise contraptions in the comics.
And, buy the best helmet you can afford, a 5 year-old helmet is just that, how-much is your head worth? Also, use a vented armored jacket, good gloves, and suitable boots when you ride. No 'squidly' shorts, sandals, or t-shirts, please (see my screen name). A healthy recognition that every time you ride your bike, you could have a life-altering accident is a good attitude to take, don't assume that someone isn't going to turn-left in-front of you, or pass you, cut you-off, and then slam on the brakes, or actually intentionally swerve to hit you, things we've all had happen one time or another. Be aware, be alert, and dress for the day when someone does take your safety cushion from you, and you have an accident. It happens.
Leave the fairy bells to the Harley boys.
