It's good to have something to work towards in life, especially in the current times. Maybe you could show your parents its something you're serious about by making it "zero cost" for them. All costs for them will come from your wallet. Offer to do extra chores for extra allowance, maybe you...
The people on this forum are all very non- judgemental and supportive, even in giving support for butchering to someone new.
I was about your age when I got into growing my own food and made a decision that I'd like to raise my own meat because I will of known the animal was loved and well...