The usual process is to see a therapist who clears you to take hormones. A doctor looks after the hormones. After about a year of living as your defined gender in public you get approval for surgery, if you want it. Many girls don't.
Ther are surgeons in many countries who specialise in the procedure. The reputable ones want approval from your therapist that surgery will work for you.
Surgery takes about two weeks, then you have to use dialators for many months and years to maintain your vagina.
It is quite a long process and can be very expensive if your country doesn't have health procedures in place for transgender people.