I'm currently a junior in high school and I can tell you it is not as bad as you think. My best suggestions are...
-Get electives you enjoy! It makes it easier to find friends, especially if you're in band or FFA
-Join clubs or sports, it's another great way to find friends as well as nourish your mind and/or body
-Take a foreign language class, this is something you need for a lot of universities. As a freshie it's not bad to not take one, but by your junior yea you should be taking a class like Spanish 1, French, German, etc.
-Keep your grades up. Elementary and middle school never counted, but this is real. You need to do well in order to get into a good college or university. Keep that GPA up c:
-If your school offers dual enrollment classes, TAKE THEM. It gets you a step ahead in life and lets you not waste precious time in money with the ridiculous core classes you have to take those first two years of college
-Study, study, study. Need I say more?
-Never procrastinate. It's a terrible habit and will really stress you out, trust me it's one I'm trying to overcome
-Avoid drama. I think this is self-explanatory
-Try to make new friends. Usually you'll find someone you like and think you can be friends with in one of your classes. High school is a great time for building social and leadership skills in my opinion.
-Strive to do your best. Try to get into your high school's NHS or societies/clubs that are similar. It looks great on a college application.
-If you can handle the work load... I suggest taking as many honors and or AP courses as possible. It helps boost that all so important GPA.
-Make sure to get your community service hours going (:
-Don't freak out! I know at some schools it's customary to pick on freshman, but even if that's so, it's not all that bad to be a freshman! It's a new chapter in your life and if you make the correct choices you'll do absolutely fine (: