Lets start with the basics.
1) did they deliver the right tractor?
2) Is it cranking, but won't start?
3)Do you have any electric power anywhere?
4)If cranking, but not starting, is it trying to hit, but fails just shy of making it?
5)As mentioned, have you check the fluid levels, especially the oil and fuel?
That should give us some idea of where to start...(no pun intended)
David from jax