It would certainly be unusual and unique! Just give it a try but you might get negative reactions from both teachers and pupils. It depends on your social role, if you an outcast or have a lot of friends.
I would find it cool if I went to class with you just wearing barefoot sandals. I would not have dared the same at your age but I was a coward, frankly speaking ... I might have secretly stared at your bare soles and not dared to speak to you (so be prepared for that reaction as well). Later in life I found that even when I go completely barefoot most don't react at all. However the social atmosphere in school classes can be special with social groups and cliques, some may use it as an excuse to get hostile.
So try it, have fun and a smile on your face, don't try to hide your feet away but be open and positive, tell anyone curious how much more fun this is than wearing sandals/shoes. Not sure if you will inspire others but at least they may think positive about it as well.