Out of nowhere the gate light came and started binging. I've tried opening it and shutting it. Nothing works.. The glass rattles on the gate.. Tried tightening everything still no relief

Before you replace the latch ,adjust the lower latch hook.
Open the Gate and lose two bolt holding the hook on bottom.
Using screwdriver lift the hook just a bit and tight.
Close the gate slowly and look if the hook is on center of the latch.
Adjust left/right if need by losing the bolt and pushing with the screwdriver.
Buy White Grease Spray from your auto parts store and lube all looks.
Good Luck

The latch mechanism is defective. It is not getting to the second "closed all the way" position. It has two parts to the latch mechanism that allow it to catch.."safety part" and "closed" part. The micro switch in the latch mechanism is informing you the second "closed" latch has not fully engaged.

In addition to Scott Carmicheals comprehensive answer i think it worth adding that it may just be a faulty earth to the gate switch so i would adivise getting that checked out before replacing the switch