Here is some lessons I have learned.
Do yourself a favor and take at least honors and AP classes. These will prepare you well for college and also look good on your resume. Don't get discouraged in one of these upper level classes if you studied for hours and the guy next to yu studied ten minutes that morning of the test and he still ended up scoring higher than you. Many geniuses walk these halls and complaining and wanting to be as smart as them will only make your work harder, it's up to YOU to succeed here.
And at last a final word
A lot of people say that these will be the best four years of your life, and indeed they could. But it is ultimately up to you to make whatever time you spend here enjoyable. My time these four years was extremely average. Never really had many friends or went out, but never go bullied or anything either. Four years of my life were basically spent only at my own home or at school. this routine has caused my soul to go numb. Do not do the same thing I did. Please go out with your friends more and enjoy these four years.
I can't believe I am at this point in my life, four years ago I used to be a freshman like you too. I understand this lamenting of time is very overly used, but it is that way for a reason unfortunately.