Bill aimed surprisingly to join a world of brainy folk? (8)
I believe the answer is:
academia
'world of brainy folk?' is the definition.
'academia' can be an answer for 'world' (academia is a kind of world). I'm not sure about the 'of brainy folk?' bit.
'bill aimed surprisingly to join a' is the wordplay.
'bill' becomes 'ac' (short for account).
'surprisingly' is an anagram indicator (a surprising ordering of the letters).
'to join' means one lot of letters go next to another.
'aimed' with letters rearranged gives 'ademi'.
'ac'+'ademi'+'a'='ACADEMIA'
Can you help me to learn more?
(Other definitions for academia that I've seen before include "Educational community" , "Teaching environment" , "The world of scholarship" , "The world of college or university" , "university life" .)