The chain should be clean, but lubed. If not then you can do that easy enough. The chain should NOT be taught. With you on the bike the chain should have a bit of slack. If it's too much or too little, you can take care of that, too.
Hopefully it will come with the owners manual which has information relative to chain cleaning, tension, etc.
The tires will have wear bars, just like car tires. If the tires are getting close to the wear bars, get them to include new tires in the deal. If they're not close then ride til they are and order some new ones.
L2V -- she's a stocker!...and gone...
2011 MG Stelvio