If you want an instant lawn, sod's the only way to go. First, prepare your soil with lime and fertilizer, just as you would for a seeded lawn. Lay the strips of sod in a staggered pattern so that the joints overlap. Make sure the seams are tight so that when the roots knit, the seams will be invisible. Make sure you roll it all out in one day. Even overnight, rolled sod will burn yellow. Keep your new lawn well watered for several weeks until new roots have penetrated the soil.
This will likely be the first opportunity to examine the house without furniture, giving you a clear view of everything. Check the walls and ceilings carefully, as well as any work the seller agreed to do in response to the inspection. Any problems discovered previously that you find uncorrected should be brought up prior to closing. It is the seller’s responsibility to fix them.