I really don't think you need a spell to stop this group of people at school from looking at you and talking.
If that's the case we might aswell all have no eyes to see with and tongue to speak with,there's an old saying sticks and stones may break my bones but words may never hurt me.(This is in no way aimed at those whom may be blind or unable to speak or have any kind of disability)Example only)
You are not in any danger? from this group so i suggest you ignore them if however they start bulling you talk to a teacher about this or your parents,we go through life with people not always lkiing each other you will almost certainly find that everywhere.
Spells are not always the answer to lifes problems,mundane way first.