Can you join a church without your parents joining too?
I did. My parent had no interest in church, so I joined a church I found when I was 14. Still a member 16 years later. But if you are asking, "Can you join a church against your parents wishes?" That's a different story. If your parents are already a member of a church and what you to go with them, but you want to join a different church, I'd suggest staying at your parents church until you are an adult (unless they are obviously preaching against the Gospel).