You can t start any business if you are under the age of 18 - you are not old enough to sign contracts, which rules you out for a few years. In any case, you have the cart before the horse here. First you have to have a goal in mind about what particular issue you wish to form a nonprofit to help and find out if any other organizations already exist that serve that population. You will need a good idea of the scope of the problem that you want to address, and a solution in mind before you can even start to establish a nonprofit, or any business for that matter.If you are interested in charitable works, you should find a local charity that supports a cause that interests you, and volunteer there so that you can help the organization and get an indea of the work and effort that is involved in running, funding, and promoting a charity before you consider starting your own.
lots of government paperwork needed to start an official non-profit charity
