Intermittent no start issue

Okay, so vehicle always starts for the first time of the day. It also will start after a trip, when it’s been allowed to sit approximately twenty minutes before restarting. The problem seems to be when you make a stop for only five to ten minutes and then try to crank it again. It will sound as if it is cranking, so you let the key go to the run position and then it just keeps “sounding” like it’s cranking like turning over and over, but then will just stop. If you press the gas while it’s doing this, nothing happens. No gas is delivered. We have all new spark plugs. Definitely doesn’t seem to be the starter or the alternator. We have thought possible it’s a crank sensor? Nothing shows when hooked to computer. No codes. Any ideas of what this might be? Crank sensor? Fuel relay? Some sort of temperature gauge? Help! This is our daughter’s first car and I don’t want her stranded.