glitching

I am Sabhis, and i play Minecraft, of course, and when i play Minecraft with my friends at school during 7th hour computers, we have free time and when me,Brady,and Jarrett play it it always glitches out when I do things such as open my inventory. now im a total noob at Minecraft but i play it at home and it doesn't have this problem. I was wondering if you wonderful Mojang people could look into this and see if there is anyway possible to fix it?