I am trans myself. I’ve been researching transitioning since I was 14. The most a doctor will do for someone under 16 is puberty/hormone blockers and that’s after parental consent and at least one letter from a mental health profession but sometimes they require two letters from two different professionals.

Getting transgender related surgery is hard for anyone, regardless of age. Doctors are hesitant to perform them on people over 21. In a lot of states, they require a letter from a mental health professional. Health insurances don’t usually cover these surgeries, but some of them do if the individual can provide proof that they’ve socially transitioned and have been in therapy for however long they require.

The youngest I’ve seen someone get a trans related surgery is maybe 15–16 and that was an FTM mastectomy which is easier to get, but those teenagers have parents who are supportive enough to consent and most likely pay.

You have Google at your fingertips. I suggest you start there.