what to do

Let it sit for a day. Check the oil level. If it is low add oil and start it. I have flipped upside down rolled it over let it sit for an hour and started it. If no oil came out don't worry just wait for oil to go back in the pan. If oil came out it may be low so just make sure you have oil to pump. Let the oil drain back down to avoid needing to replave a valve cover gasket. Oil will only go where oil goes. You just get extra in some places and less in others. That is why you let it sit. To be honest I have had friends roll the truck over and fire it up and go. But thise were toys they were always rebuilding the engine anyways. It is your engine so I leave it to your call.