The flesh should be firm, not elastic in any way. Inspect the entire pumpkin. Stay away from pumpkins with bruises, cuts, scratches or any signs of mold.
Rinse under cool water if there is dirt that is not easily wiped off you can use a produce scrub brush.
Pumpkins will last around 2 weeks if they are not cut and left in 50-60 degree temperature. Once a pumpkin has been cut it will roughly last about a week for viewing if using a pumpkin for consumption use immediately after cutting pumpkin open.