I can't close the trunk, I opened it. Then tried to close it and it wouldn't shut, the peice that is supposed to click into the metal isn't turning, it's basically the lock didn't reset to the proper spot

Try spraying the mechanism with WD 40 and manually manipulate the lock. Make sure the latch has not somehow moved to a closed position even though the trunk is open. With the trunk open look at the locking mechanics and click your remote and see if anything is moving.

Close the trunk.... Just kidding

this might sound odd but it sound like the sensor that sees the trunk as closed is either mis adjusted or faulty.

spray a squirt of penetrating oil like wd40 into the receiver that secures the trunk lid. For example the lid should have a loop or square of metal that when the trunk lid is closed joins with the locking mechanism.

Shoot a a squirt of we 40 into the locking mechanism and see if the light goes out.

truck? you ment TRUNK.
some latches can be closed, with open door or trunk.
what you do is trip it.
look at lock and fiddly parts and it goes click..
look at the latch, is the actual latch close with open trunk. yes, BINGO

Its time to replace the battery. This is common in Chevy cars, if the battery goes bad it doesn't hold a charge anymore. Whats happening in your case is the low voltage isn't keeping the trunk relay closed. When you turn the key all the juice goes to the stater and lets the truck pop open. Just to prove my point, give it a jump start and it will fire right up and the trunk will stay closed.

If you can open the trunk with the key, do so. Then disconnect the battery ground cable for about 15 seconds, and reconnect it. Maybe that will clear the ECM and allow the roof to close and reset the light. Then close the trunk.
Good luck...

I did this to my car once. Be sure the latch isn't closed as you are trying to close the trunk. With the trunk open pop the trunk once, then see if the trunk latches properly.

open up the trunk, and look at the metal seam that goe's all the way around the edge of the trunk area, the weather stripping, that you described should go somewhere along this area.

there is a little finger in the latch that closes when the trunk is closed chances are that the little finger has closed but the trunk is still open... this can be fixed by looking at the latch on the lid you will see a slot with a metal arm in the middle take a screw driver and place it in the hole in the slot at the top. press the button on the fob to open the trunk while your pulling down on the screw driver the little latch should twist letting the screw driver move through the track and pop out now alowing you to close the trunk and being happy again.

Try a screw driver,and release the trunk release at the same time and unsnap the latch,the latch thinks it is closed,because the latch never opened back up to allow the striker to go in it and trigger the latch to close,the latch is in closed mode,you will have to manually unlatch the latch sort of speak.

It may just be the latch is worn out. They can be replaced.