At the end of the year, FeederWatch sends out a detailed newsletter summarizing the results and analyzing the data. I strongly advocate following your own interests. Keep in mind that studying science on a high school level, while fun, is more serious than what you've done before. Be prepared to spend time on reading, as well as allowing yourself plenty of time to play around, experiment, observe. Normally, high school courses run 4.5 to 6 hours a week.
Physics generally begins with a study of mechanics.
There's lots of room to play with pendulums, explore why air hockey works, and experiment with bows and arrows. Moving on, one studies relativity, properties of matter, heat and light, sound, electricity and magnetism. Usually physics ends with study of the atom and radioactivity. It begins with the atomic theory, where physics left off, and studies how atoms stick together to make the stuff of which we are created. There's acids and bases, chemical equations, environmental chemistry, study of foods, drugs, and even the human body.