Engine will not start up can you help me?

Just bought a 1995 Ford F150 and went to start it to drive it on the trailer and the guy said it was out of gas so I went and got $20.00 of gas for it and reset the fuel pump shut off switch and it started right up for 4 seconds then shut off and kept trying but no luck. Winched it on the trailer and got it home and then the guy told me he had been driving it and it started smoking so he had it towed home then they got it home and drove it in the yard for 10 minutes and ran it out of gas and kept cranking on it. When I got it home I put a brand new battery in it. New plugs and wires in it. New starter and fresh gas. When I checked the oil it was 1.5 quarts low and the antifreeze was empty. When I try to start the truck is turns over slower then usual even with a new battery and starter and it smells like gas and wants to start but wont then after trying for a hours I tried starting fluid and it started for 30 seconds and then shut off. So I tried starting fluid again and no start and then later that day while trying to start it I saw white smoke coming from the rear passenger side of the motor and it smell very unusual and bad. Still cannot get it to start. Don't know what I need to fix.