>>3616228>What's a good way to tell whether a roll of film has been used or not?>The roll of film has a small tab of film sticking out from the slot.Pretty much if the leader is sticking out it hasn't been used but you never know, the only way to tell is to get the roll developed.
I've bought bulk lots of expired film where one roll had the leader out but was already shot on, leading to my images looking like pic related. They were using one of the 35mm point and shoots with the "panorama" mode.
If you shoot it and get it developed you could either get the images you took or you could get some double exposures that might look neat.
If you get it developed now you either come back with a blank roll of film and wasted money or photos your parents took 20+ ago (most likely your parents nudes)
Pick your poison.