It will come with one plug in the engine.
I would recommend the following:
AA batteries; you can get any brand, but I like Duracell - they seem to last longer.
Fuel: 20% trinity monster horsepower is what I like the most. I've ran most of the fuel types out there, and trinity, by far, is the easiest to tune.
Fuel filler bottle: mines' a dynamite brand one, but Venom makes a decent one too.
Afterrun oil: 1 part Automatic Trans fluid to 1 part Marvel Mystery Oil is perfect - it's cheap, and you'll get a year+ supply for about $16. You will need a bottle to contain this. I have an oil bottle that I picked up from a sewing machine repair shop (hey, don't laugh; I had to pick up my moms' machine and spotted the bottle). The bottle cost about $5, but it has a long tip with a screw on cap - perfect for After run oil.
I would also recommend a temp gun: you don't need a real expensive one. Duratrax makes one that's cheap and fairly decent.
Lastly, you'll need a tool for the glow plug; an 8mm socket is all you need. When tightening the plug; just snug it, NO gorilla force needed.