I haven't changed anything about my life but all of a sudden I am hearing someone tell me to kill myself is this even possible? I can't figure out who is telling me this. I am always in a public place but there is not a one person that is always there. Am I hearing things? Can hearing voices start when it's never happened before?

Yes it can, and its probably for an easily treatable condition you have developed, You can speak to your doctor who will likely refer you to a mental health provider for diagnosis and treatment..

mh - how old are you?

I am 17

That's the most common age (late teens) for schizophrenia to develop. Try not to be afraid, because I can't possibly know if you have that or something else, or are just very stressed, or have a physical condition. I know someone who was hallucinating and it turned out she was hyperthyroid! I was straightforward about it, however, because the sooner you get to a clinic, the better. You may need a complete checkup before a referral to a mental health therapist.

Where (generally) do you live? Do you know what's near you for help?
You do need to tell your parent(s) or guardian. If they don't believe you, talk to a teacher. If you have a school nurse, that's the best person to tell first.

Are you ingesting anything unusual, in the area of nutritional supplements, teas, pot, other drugs? Do you have any huge stresses in your life right now, or other unusual symptoms?