Novice maybe finding Aintree tricky (7)
I believe the answer is:
trainee
'novice maybe' is the definition.
'aintree tricky' is the wordplay.
'tricky' indicates anagramming the letters.
'aintree' with letters rearranged gives 'TRAINEE'.
'finding' is the link.
(Other definitions for trainee that I've seen before include "As pupil" , "Person being taught" , "Aintree (anag.)" , "one needs to practice" , "Apprentice" .)