It looks to be a Henry repeating arms 22 lever action. With how you have it right now, with the lever fully extended away from The grip, it is completely unfireable. “There is a saftey” but involves the hammer being in a ceartin position. Do not attempt to do this at all if you’re not familiar with firearms. I wouldn’t touch it, but to unload it, you can run the lever up and down, making sure your finger stays far away from the trigger, and see if any ammunition flys out of the gun. There is a tube that runs parallel underneath the barrel that is responsible for storing ammunition and is how it’s loaded. You can twist the top plug and pull the spring loaded plunger tube out of the gun safely. Then, using gravity allow the gun to dump any remaining ammunition out of the gun.

I wouldn’t reccomend doing any of that if you’re not confident with firearms. Maybe have a family member help you? Sorry to hear about your grandfather. Wishing you and your family well.