what can I do if my school is difficult to participate in, especially since we have to test into honors and AP classes?
I go to a public school in New Jersey, my school is very strict for some reason when it comes to honors and AP classes. They make us test into the class. Last year as a freshman, I took the honors test for chemistry and world history. I didn't pass the chemistry one but I did get into World History honors. They don't give us any study guides and half of the stuff on the tests we don't know. My goal is to go into an IVY league such as Brown. However, at this point I don't know if that will be possible since I've only taken one honors class so far.... what can I do if my school is difficult to participate in, especially since we have to test into honors and AP classes?
Try attending things outside of school. Community service is always a boost as well. Finding new hobbies that you can improve on your own also helps. You could find a certain hobby and open a club in your school.
Also, if your school lets you take community college classes, you should do that outside of schools. You could (depending on what grade you are in now) theoretically get an A.A. or A.S. degree if you take enough credits. Also, Coursera is a good resource to take classes in computer science, physics, history, etc. Another thing you could do is register for summer immersion programs at some universities. Of course, some, like Columbia are hard to get into, but a lot of local state universities (for example the University of the Pacific where I come from) let high school students take summer immersion courses.