ahh 7th grade, good memories... my middle school was messed up because we were an "epirimental trial" group... instead of books, they gave us laptops and no blockers!
but onto the social part... i really cant help with the amanda thing aside from a simple either talk to her face or leave it be speach.
the sevent grade social part however... what helped me was 1. get contacts, 2. stop wearing lego and cartoon shirts, 3. don't answer every single question the teacher asks.
that's about all i can say, oh and 7th grade isnt that big of a deal, its just 6th grade again with more kids this time. that and you get more than one teacher!