At this point in your academic life, there are two important things you might want to consider:
Learn other languages
You might think this is a strange piece of advice, but think about it for a minute. Archaeologists come from all over the worlds to dig up important archaeological sites of a given civilisation and the results of these excavations are generally published in the native language of these scholars. Even though many archaeologists now publish in English, the Germans write most of their books and articles in German and the French write everything in French! Starting to study languages when you are young is much easier and by reading in different languages, you will have access to much more information for your research projects.
NOTE: Some universities with programs in Egyptology have modern language of scholarship proficiency prerequisites (in other words, you have to take reading comprehension exams in languages important to your field of study). It is necessary to successfully pass these before even being allowed to continue to the PhD programme or write your thesis. Why not get a head start?
Keep up with your other topics and hobbies
Archaeology is much more than just digging the dirt with a trowel. Many archaeologists have scientific or artistic backgrounds. You love sciences? Archeologists often have to make scientific experiments to test their hypotheses (especially if you are interested in ancient materials and technologies). Make sure you keep up the good marks, they are required if you want to register for a bachelor’s degree in sciences. You are talented and like drawing and photography? Archaeologists always have to take photos and make drawings of the artefacts they find. Practice your skills and make a portfolio of your work.
Also, since all archaeologists have to write site reports and articles or books, make sure you know your English language and grammar well.
NOTE: Refine your skills!! Many secondary schools have science or photo clubs. Joining one is a good way to practice and show your talents! And make new friends, too! Many towns and school boards offer community courses in a variety of fun topics. Registering for one could be lots of fun and, at the same time, you are refining your skills ! You’re a wiz kid who has always loved school? Tutoring younger kids and helping them with their homework is something you might want to consider if you are interested in teaching (many archaeologists are university professors). The money you earn can help you buy that interesting but expensive book you saw at the bookstore!