Howdy,
Here's a few other things to add to Buck's excellent advice.
Used shotguns are a tough thing to figure, especially the older, original guns that are widely available. We use out guns a lot, a whole lot, and these older guns may not be ready for the workout. I would strongly suggest that as a new shooter, you buy a new Baikal or Stoeger, if you can not find a local pard who is selling off one of his extras. Both of these new manufacturers offer longer barrels, just look around. The Stevens 311 is pretty much bulletproof and is the lone exception to my used gun advice.
I would be very cautious in buying a 97 until you've seen a few, shot a few AND have located a good gunsmith, cause they are complicated machines.
Welcome to the game and good luck.