At least you said "not turning over" - that is huge piece of info.
Coach Geo got the top ones.
I 'll ask a few questions.....
was it hard to turn over the LAST time it ran? if so - check battery and cables.....
Batteries can go bad - quickly, but most time they let you know they are losing it....
IF the last start was "normal" - then check all them little safety switches.....cause them little sum beaaauches will drive you crazy! As you turn the key, move a lever or two and see if anything changes................report back what you find.