If it backfired a few times before it stopped working it's your plug they might look fine and give spark but they could still be dud
I cleaned the spark plugs and changed the oil. I shouldve checked before i did those but i tried starting it and it wouldnt start. Then i put it in first to see if itd move while i held the clutch n it wouldnt move, the back tired would stop. What does that mean??
Did you try push starting it? Was it running as good as usual before hand. Sometimes the exhausts on two strokes get clogged.
Those are cool bikes . If it's new to you I would suggest pulling the spark plug to see how it looks . If it is dark and oily you will need to adjust your fuel mixture .