After my research we've decided to try to use a pack n play for our baby to sleep in our room for 2-6 months most likely. (The nursery is across the house and our room has room for it.)

This is the one we decided on (pic below) the graco playard with bassinet.

My question? I'm assuming (please excuse not-yet-a-mom stupid questions haha) the baby sleeps on that top part, right? Well when I looked at it, it's thin and doesn't seem to have a way to attach a sheet. It was recommended I get sheets so when I checked it out I was confused. Would you let baby sleep on the top part there without a sheet? What do you do if the baby soils the PNP without a sheet??? I believe I have read to not have baby sleep on non tucked-in with elastic edges sheets or blankets etc, because they could bunch and potentially suffocate baby.

So moms... how did your newborn use a PNP?? (Only interested in specific experience with the Graco ones) Hope this is just a stupid question with an easy answer!