Powerlifting is open to everyone - there's a weightclass and age bracket for everyone, and you pick what you will lift so it's very accessible. If you are curious about it, ask your parent to help you look for a local meet on Powerlifting Watch and go watch one, usually $5 on a Saturday. People are typically very friendly at meets and it can be a good place to ask where good gyms are to get stronger if you decide to start training for a meet.
You don't need a powerlifting gym, but it is usually best to have some kind of coach or team to help you with your lifting technique and to guide your training into a competition if you decide to try one!