Went to start my truck and it started for a second but made a loud popping sound from the engine bay, I looked and found 2 little hoses detached from this.

I reattached them and started the truck but it made a hissing sound. Anyone know what caused this and how to fix it?

 

You had a "forward fire", opposite of a "back fire"(out the exhaust)

That should only happen if the engine is already warmed up
Air/fuel mix enters a cylinder that's still hot and it explodes while the intake valve is still open, which causes high pressure in the intake which is normally only low pressure, vacuum
OR
Cylinder misfires but fires but fires as intake valve opens

Vacuum lines don't need hose clamps because its negative pressure so they can't be pushed off "usually", lol
Power brake booster hoses usually have hose clamps for safety reasons

In any case its rare unless you have a failed intake valve, it's not closing
The hiss is from a vacuum hose that is still off, have another look around, i.e. if a hose did NOT blow off at the intake then its other end probably did