It's a two-stroke.
NGK B8ES for the plug, get a few extra and put them in the crossbar pad.
Valvoline 20-50wt. conventional oil or any name brand synthetic type oil for the tranny. Replace it after every hard day of riding!
Clean and replace the air filter with a proper one :) , K&N if you plan on keeping it, or any of the good foam ones if you don't.
50:1 ratio with premium or race gas to a good brand of 2-stroke oil, Yamalube 2 R, Klotz 50R, none of the conveience store junk, it'll just load up everything with spooge, if you spend money anywhere, spend it on GOOD 2-Stroke Oil!