Question: I want to be a model/actrice. How do I get started?

I'm 5'9",
skinny shoulder length brown hair,
brown eyes,
light skin,
teenager.

Answer: Your physical attributes are what they are. If you want to become an actress you will become one. With regard to acting remember that you need to work backwards and don't put the cart before the horse as we used to say.

If you start contacting agencies, you will need to be prepared for the meeting. To be prepared for the meeting you will need to know what to expect. To know what to expect, you will need to inform youself. In order to inform yourself, you will need to find people who can explain what it's like. You could also very well be asked to perform a monologue. To perform a monologue well, you will need some training. To get training you will need to go to school. Before you go to school, you will need to search for a school, the right school and be sure that that is the right school for you. In order to do that, you will want to interview different schools.

To find the right school and the right acting technique for you, you will need to know what the different acting techniques are or at least be familiar with them. It would help to know what you are looking for in a teacher, but that will probably come later after you have had some experience learning the craft.
You will also need to think about what your budget is.

AND THEN, starting over again, but correctly this time, you will want to start contacting agents and promoting yourself. In order to find THE RIGHT AGENTS and promote yourself in the right way, you will need to know at least a little bit about the industry and about which casting directors cast for the types of projects that you would be right for and which agents they usually work with, or rather which agents usually are informed of and submit their clients for those types of projects. To know that, you need to study the industry. To study the industry, you will need to read books and trade papers, navigate on the internet, attend seminars and classes about the business of acting, talk to other actors, go to plays, movies, watch television and do just about anything that will help you learn as much as you can.

There's lots to learn if you're up for it.

Have a look at this page link. I put it together for youngsters just like you. I think it will be a good start for you.

Tony