wildfire 50cc atv wont start

Ok, so a few years back my uncle picked up a little chinese atv it had a carb problem, I haven o idea what…maybe it wasnt jetted correctly and anyways it wouldnt start so my uncle fixed that and the atv got flipped and wouldnt start so its been sitting in the garage ever since so today i tried to get it started i tried to put it on the battery charger but when i pushed the start button it only made a click so i then tried to push start it and it was turning over but wont start, so finally i quit working with it I also noticed it was leaking a little gas by the fuel petcock. Any advice to get it started? Thanks…