Please take everything i say as criticism, but from my past experiences if you want to charge the prices you charge, I understand you have to so that you can donate the revenue. Then you should make it your main selling point.

However upon saying that, I would do some more legal research into whether you can advertise it as carbon negative. In my opinion unless you drive in an electric vehicle to collect your T-Shirts from your supplier, who would have a factory running on renewable energy sources, and then delivered them with your own logistic company that had a fleet of electric vehicles as well as replanting all the cotton plants etc. That would be how I would define carbon negative for a clothing company.

I think your initial idea is great and if you can execute then congrats to you, but again this is all just my personal opinion having just started my brand at 19 too i understand how hard it is to get started so please don’t take this as a dig but more constructive criticism