Gas leak

I think more and likely your fuel line's disconnected

Do you know how would I connect it back?

Yes, the fuel line could have disconnected, try to take a good look at the area where you see the fuel collecting on the ground and this will give you and idea where to check. My friend had a fuel leak in his Honda Civic but it was the housing of the fuel pump that had cracked. The pump is inside the fuel tank located under the rear seat. Do you smell gas inside the car? In any case, be VERY CAREFUL, dealing with fuel issues is dangerous, if you don't know, get a mechanic.

Depending on how it's disconnected. If it's just a hose that came off the fitting, it just goes right back. But if a hose is broken, it can be repaired with coupling but if the metal part in your lines broken, it will have to be replaced.

No, it only leaked when I tried to crank it. I just need to find out where it is coming from so that I can fix it because I really need my car.

Where was the leak when you first noticed it? Do this, just turn the key to the on position, don't crank the engine, look under the car and check for gasoline leaking. Again BE CAREFUL!

Have someone coming out today to diagnose my car, I hope it's not an expensive fix