Also congrats on the solo. I remember mine - I was flying in an oat field. There was a knocked over silo behind us. My instructor who usually stood beside me, walked back and took a perch up on the silo. I said, where ya goin? He said you got it. The rest is history.

An OS 40 shouldn't deadstick unless it is ruined. Like what was said above, make sure the carb isn't closing too far when you pull back the stick. You should have about a toothpick size space at low idle. If that is fine, check the glow plug. Glow plugs can be wrecked after a few minutes of running if dirt or a piece of metal gets in your element. Also your plartinum can come off your element. Try a new one. If all that is fine, take your high speed needle out of your carb and blow air through your carb to clean it out. Dirt can cause trouble. Also make sure you didn't have a hard landing and your clunk is stuck foreward in your gas tank. Also make sure all your fuel lines are good and not pinched or broke somewhere. Check your instructions and make sure your low speed adjustment is set right. If none of these things work, your gas is bad.

OS engines are the most reliable made. I'm 100% confident that yours is fine.