Your need for financial support can have several levels:
1) Basic sustenance: Food, shelter and clothing. Sounds like while you are not living in the lap of luxury, you are hardly destitute
2) Independence: A means of transportation, a cell phone, personal goods of your own. Your own car is not the only means of transportation available to you in many towns and cities, but independence usually requires more money than many people expect.
3) Opportunity: A nest egg or financial instrument (loan) to fund either schooling or a business start-up. It doesn't appear that you have either.
4) Creature Comforts: The things everyone normally wants just for the sake of enjoyment: iPod, new pair of shoes, cigarettes
If you don't have #1 covered you need to get in touch with Social Services right now. I'm going to assume you are not destitute
For #'s 2 and 4 you need an income.
This usually means a job.
There are jobs that a 16 year old girl can get without needing a degree or a connection or even a means of transportation. Baby-sitting is an obvious one but there's also dog-walking, lawn work, and personal services (by that I mean nothing more than something like light cleaning or food shopping for older couples).
There are always people who will pay someone else to take care of things that have to be done around their house but which they don't want to or have the time to do.
There are several ways you find or solicit these kinds of jobs:
1) Bulletin boards
in supermarkets, post offices, libraries, schools etc. You can either use the boards to find jobs or to let people know your looking. Check them out if for no other reason that seeing how other people in your community are using them. They may give you a couple of idea.
2) Personal ads
in either newspapers or on-line sites. Chances are that you will not find a ton of opportunities, but you only need one or two.
3) Make up flyers
that tell people what you can do for them and how to contact you and then stick them in mailboxes in your neighborhood
4) Word of mouth.
Tell everyone you know or who you meet that you're looking for work and that if they hear of anything would they please let you know.
There are a lot of young people who want money. Some of them are willing to work for it. Some are willing to work at finding ways to work for it. If you're not willing to work, and at something you don't particularly like to do, the chances of you getting the money you want are pretty slim.
If you have a quick need for cash for something like a cell phone you can always sell what you already have. I wouldn't do this unless I had a very specific purchase in mind that was going to help me meet my goals. You know what you have. There are stores that buy used CDs and video games. Dolls and old toys kept in fairly good condition can be sold on e-bay. People buy old leggo sets on e-bay!
Don't use this approach to pay for an ongoing expense such as cell phone service. The chances are that this will be a onetime deal
To finance opportunities you are probably going to need a loan. If you're a good student you could qualify for scholarships. This is where you have to find someone at school to talk to. i can practically guarantee you that your school has Guidance Counselors and it’s their job to help young people like you figure out the best oath they can follow after they graduate. If any of them are worth their salt, they will know scholarship or loan opportunities at community colleges and even about trade schools (beauty school) and where to go to get public assistance for that as well.
Do it now so that if there are things you did to do in advance of the opportunity you can get started and get it done ASAP.
One important word of caution with all of this
Be smart and be careful and make sure you're not getting yourself into any situations that could be dangerous. It's not like all the perverts and crooks in the world are just waiting to go after you, but use common sense and don't take unnecessary risks. It would be best if you could talk to a responsible adult about your plans and ask for their advice, but if you can't you can still move forward as long as you are careful.
Success breeds success and one accomplishment makes the next one easier.
You can take charge of your life and make of it what you want or you can just sit back and wait to see where it drops you off.
I hope some of this or any of this is helpful, but as corny as it sounds, it really is all up to you.