Well, truth be told, sometimes surprisingly little. Everything needs to be checked, gone through and cleaned up, but much of the stuff can be re-used after renovating it. You will probably need to replace a few oil seals, some seals in the carbs maybe, but mostly it's going to be renovating what you got. And you won't really know what you need until you start going through things.
I suppose you could start laying in some supplies and maybe a few "specialty" tools. You'll want a basic solvent for cleaning off the oil and grease (I use kerosene), some chrome polish and aluminum polish (like Mother's). For the rubber, vinyl, and plastic parts, wiring especially, I use a product called the Tannery. It does a great job of cleaning and preserving all that stuff, and it's easy to use. It sprays out like a foam and you just let it soak a bit then wipe it off.
For tools, this is a metric bike so if you don't already have them, you'll want to get some metric wrenches and sockets. Also, one of those hand held impact tools you hit with a hammer. You most likely will need that for some stuck on fasteners you'll probably encounter. There's more, lots more, but this will get you started.
