wont start

I purchase my motorhome about ten days ago. I drove it home it was a little hesitant but trolls never stalled drove around for a few days. I drove it down to my buddies house it was kind of part shipped towards the fuel pump size it idled for about forty minutes shut itself off and did not start back up. I changed all the gas drain the tank yesterday changed all the gas change the fuel filter. You started it back up I drove about two miles it sputtered and popped it shut off and would not start again just kept turning over and turning over and turning over. any suggestions of what I can try or maybe what is wrong with my motorhome? it is my daily driver I have an Autistic son and this is how I get him around because he has sensory issues. I really need to get this thing running again.