I agree with Keith 100%. A career in science can be the most rewarding ever.
At your age, I'd suggest reading some biographies of famous scientists -- your librarian can help you find good ones that are fun to read. Another way to get "turned on" is to play around with the internet, for example
http://powersof10.com/is fun (use the scale control bar at the far left to make it work) -- it brings together knowledge of the universe from the tiniest to the largest -- some trip.
On the academic side, algebra is to science what reading is to general learning. Master basic algebra and the rest of your science and engineering studies will much easier. Next properties of matter (material sciences) is fundamental to most everything. There are a lot of 1st year college texts that cover this material. Here is a link that might be a little advanced, or maybe not, take a look and see
http://phet.colorado.edu/en/simulation/states-of-matterIMHO, it's too soon to worry about job markets; these vary from year to year. Naturally engineers who do applied work are generally paid more, while "pure" scientists have more freedom to pursue their own interests. Keith is right, however: learning science will develop your knowledge of the real world and your ability to think. These are invaluable whatever you ultimately choose to do.
I have never regretted choosing a scientific career for a moment.
Good luck!