Mixed Public to All Boys Grammar, What can I expect?

Hi guys, as the title says, im going from a mixed public school in a fairly deprived area, to an all boys grammar in a slightly nicer area. What can I expect as major differences, I achieved very well in my GCSES, and I know that would be considered average there. But I am very nervous going into this new school.

When you say "public school", is that what you really mean? A "public school" is, counterintuitively, a fee-paying school. You say "in a fairly deprived area" -- but that's exactly the sort of area where you won't find a public school!