I'm confused. Even further confused watching your video. You aligned it, but you couldn't get the engine to start? Did you try to start it after you replaced the belt? In your video, you're turning the cam, but it looks like the belt is still attached. You should never try to turn the cams to turn the engine, only turn the engine from the crankshaft. If you tried to start it with the belt not connected, then yes, you've probably damaged some valves.
If the belt is still attached, turn the crankshaft ONLY, and only turn it clockwise looking at the crankshaft. Line up the marks on the crank, make sure the #1 is lined up on the cams, and if not, turn the crank one more turn and line up the marks.
If the belt is still attached, turn the crankshaft ONLY, and only turn it clockwise looking at the crankshaft. Line up the marks on the crank, make sure the #1 is lined up on the cams, and if not, turn the crank one more turn and line up the marks.