ok so yesterday i was riding around with my friend doing like 2 stairs 3 stairs and today when i tried to ride my Uni the stupid wheel was flat! What do you think happened…My friend was doing the 4 stair and his wheel is fine so what is different about mine?! 
Thanks!
Shit happens. If you don’t have a patch kit, you might want to look into it.
Probably a pinch flat. If you can get a 16in motorbike innertube, I’ve gone off 5ft drops with low pressure, so low I hit rim. I did that over, and over yet it is still going strong. This is if your have a trials uni of course.
What’s different is yours has at least one hole in it. Probably two. Look up “pinch flat” if it doesn’t mean anything to you, but basically it’s the likely thing to happen when dropping if your rim hit the ground.
You can beef up the tube, or just use more air. That’s after you fix it, of course. Remember not to go by any air pressure numbers someone has listed elsewhere on this forum unless they’re doing the same drops with the same rim and same exact tire, they weigh the same and they have the same riding technique. In other words, adjust your air for best performance, making sure you’re not banging the rim onto the ground.
Ultimately your rim will never touch the ground, but nobody’s perfect. That would mean running way more air than you probably want. so you keep adjusting it and riding accordingly, until you find what works for you in the type of riding you’re doing.
It might not be air pressure
The above advice on pinch flats is good. But if you are pretty sure you had enough air, you probably got a tiny puncture, to small to hear or notice at the time, but enough to go flat over night.
You need some tire irons. Once you get one side of the tire off the rim, pump up the tube and paint it with soapy water. If there is two damaged spots (one for each side of the rim) , it was likely a low pressure pinch flat. If it’s just a tiny hole, rub a rag on the inside of the tire to see if it snags on something. You can patch a small hole without even removing the wheel, but if there is a pinch crease, maybe a new tube would be better.
If you are new at this, don’t be surprised if it goes flat again soon. It is very easy to pinch a new flat into your tube while levering the tire back on. Be super aware not to do that.