When I looked at gliding it seemed like you'd spend all weekend every weekend hanging around the field ...
... out of which you'd get one ten minute flight every fortnight, if you were lucky.
Far better, if your family is actually happy for you to be absent all weekend every weekend, is to spend all weekend every weekend working overtime until you've saved up enough for the PPL. The advantage of powered flying is that a one hour lesson only takes around three hours, as compared to a ten minute lesson taking four days of your time.