Surprised when beginning was first? (8)
I believe the answer is:
startled
'surprised' is the definition.
(similar in meaning)
'beginning was first?' is the wordplay.
'beginning' becomes 'start' (start is a kind of beginning).
'was first?' becomes 'led' (to lead is to go first).
'start'+'led'='STARTLED'
'when' acts as a link.
(Other definitions for startled that I've seen before include "Suddenly alarmed" , "Taken by surprise" , "Affrighted" , "Scared" , "Taken aback" .)