The ammo is bird shot. Very low pressure. Shoot it at pop cans from about 5 yards away and enjoy!
btw... forget about any "safety" on that rifle. Just use the 10 basic rules and you'll be fine.
1. Always Keep The Muzzle Pointed In A Safe Direction
2. Firearms Should Be Unloaded When Not Actually In Use
3. Don't Rely On Your Gun's "Safety"4. Be Sure Of Your Target And What's Beyond It
5. Use Correct Ammunition
6. If Your Gun Fails To Fire When The Trigger Is Pulled, Handle With Care!
7. Always Wear Eye And Ear Protection When Shooting
8. Be Sure The Barrel Is Clear Of Obstructions Before Shooting
9. Don't Alter Or Modify Your Gun, And Have Guns Serviced Regularly
10. Learn The Mechanical And Handling Characteristics Of The Firearm You Are Using
Common sense rules the day.
If it were me, I'd shelve that ammo and go get some typical .22 LR ammo and use that. The bird shot is for rats and black birds "up close", and really isn't wort a hoot for much else. Heck, I'd be tempted to toss it in the trash, really.
EDIT: a quick search shows that firearm, a "Mod. Tex .22 LR", to be worth $30 to $100, probably made in Germany and imported via Miami, FL. The company is long defunct.