As mentioned, it could be any number of issues. Most of which can be fixed without a lot of drama. I happen to be of the opinion that, any firearm I acquire, gets a thorough cleaning, inspection and lubrication. It's a good way to learn about your new friend.
Worth remembering as well, Illustrated parts breakdowns and how-to videos are a simple internet search away. Some are horrible and some are excellent, you just have to wade in and sort them out.
Also, before I forget: Pics ??