First step is to field strip it and give it a good cleaning.
After all these years the lube will have dried out and the action will probably be dry and sticky.
Re-lubricate it with your favorite lube, and use a grease on the bolt and operating rod.
Here's the US User and Ordnance Field Manuals. These will tell you everything about how to disassemble and care for it.
Note the info at the top about what password and username to get access.......
http://www.biggerhammer.net/manuals/
You should absolutely shoot it.
It's a standard re-built Carbine with the later features like the milled adjustable rear sight and bayonet latch.
The GI carry case is itself a collectible and worth some money.
Why do I never get great deals like this?????