Assuming the bike was stored indoors, I'd change the engine oil, replace the battery, replace the gas, and inspect the tires. Nothing else is going to go bad in only 3 years. I have a lot of experience with this sort of thing. It's no big deal. So don't get paranoid. Enjoy your trip.

 

My bike had been sitting for 3 years when I bought it. Changed all fluids, plugs and battery and good to go. Check tires. I rode them 2 more years, then changed them out even though tread was OK. Just at that point they were 8 years old.

 

Thanks to all the posters...gonna change the fuel filter, change the fluids,check the tires, test ride it, throw on the leathers, plug in a Jerry Jeff Walker CD and hit the road...figuratively speaking of course...been too long without...
I'll let you know how it went on the back side of the trip.