Perhaps the best (and the most easily accessible) option available to most young people is the chorus at their school. Many high schools and colleges offer a chorus program of some kind and though what that looks like differs from location to location, the idea is usually the same and there are plenty of benefits, no matter what shape the program takes.
When I was in high school, Chorus was offered as an actual class which gave students an opportunity to express themselves creatively in the middle of a day usually filled with much drearier courses like math and science. I knew many people who selected Chorus as a field of study and they benefited immensely as it didn’t require them to give up any more of their time than they normally would have during the day and they got to practice singing often.
Sometimes Chorus is only offered as an after-school extracurricular, although this doesn’t typically diminish what it can do for those just getting started as vocalists. The fact it only takes place after the final bell has rung does mean some students can’t participate since everyone has a different schedule and between homework, familial obligations, part-time jobs, and a normal, healthy social life, not everybody who wants to can sign up for an extra hour or two after the school day has wrapped.
Now, while Chorus is a great introduction to singing for many young people, it’s usually just the first step in studying vocal performance. Many Chorus Teachers have obviously been involved in music for a long time and they have learned how best to instruct students in the art of singing.
However, if you decide you want to pursue singing after high school (or even during), you will need to work with others to further sharpen your talents and take your skills to the next level, such as College Professors, or perhaps even private vocal lessons.