There are backpacks designed for laptops and come with pencil cases built in…or buy a briefcase
my advice wud be ………. dnt buy a laptop…… buy a netbook………….it is much lighter and small in size,,,,,, so it wud b much easier for u to carry it…….. and after all u r a school student………. right now u wdnt have so much need of a laptop….. u wud need ur laptop when u will b in college……. so if u buy a laptop today it wud b outdated in those times……. and netbook is a better show off than a laptop
hope this helps u