Do I need to buy a brand new little plastic latching thing for EVERY time I go mountain climbing, or can I just re-use the old one I have? Last time, when I went with my mom's friend, we only used one and it made some weird noises, so I was just checking. Thanks!!!!!
Don't waste your money. Once it breaks completely, just go out and buy another. They don't cost much, but I'm a pretty fiscally conservative person. If you don't need it, don't buy it.
I HOPE you're not talking about a carabiner (the oval or d-shaped 3 to 4 inch long spring-gated clips that are used to manage and connect the climbing ropes and harnesses.) Though many are brightly colored (by anodizing) they are made of steel, not plastic, and are rated to withstand 1000's of pounds of force.
Though many stores sell cheap versions these are only meant to be used for keychains or toys and are absolutely not safe for climbing. A tested and climbing rated 'biner will have a weight rating stamped on the metal (like 3,500 or 4,000 lbs.) and you will only be able to buy one in the climbing gear department of a sporting goods store. Of course a real 'biner can be re-used -- as long as it has not been damaged or subjected to maximum force on multiple lead climber falls (which should not be an issue if you are just learning to climb.)
I hope you are climbing with an experienced person who has adequate gear and knows all of the safety measures. They should be able to advise you on the selection and use of the equipment you are using. Don't risk injury (or your life!) by climbing with somebody clueless.
Yeah, just use it til it breaks, but hopefully that's not while you're climbing!!! They have some cheapy ones at most dollar stores, if you need a replacement.