Having some familiar faces in your new high school environment can help a lot because you are not completely alone during your first few days, but you shouldn't become completely dependent on them. Don't be afraid to branch out into other friend groups and find more people you are comfortable with. It is important to keep contact with your old friends, but you can't grow as a person if you don't branch out and find your own interests and friend group. Befriending new people can also make you more excepting of other people's interests and expand your own. A new friend could introduce you to something that they like, and you could end up liking it as well.
For example, in my freshman year, I became friends with a girl who introduced me to the show Doctor Who. It has since become one of my favorite shows, but I never would have taken interest in it if I had not ventured outside the small circle of people from my grade school. New friends can introduce you a sport, book, TV show, movie, or any other after school activity that you might not have discovered otherwise.
For example, in my freshman year, I became friends with a girl who introduced me to the show Doctor Who. It has since become one of my favorite shows, but I never would have taken interest in it if I had not ventured outside the small circle of people from my grade school. New friends can introduce you a sport, book, TV show, movie, or any other after school activity that you might not have discovered otherwise.