Attention needed at first to make money (4)
I believe the answer is:
earn
'make money' is the definition.
(I've seen this before)
'attention needed at first' is the wordplay.
'attention' becomes 'ear' (ear is a kind of attention).
'at first' suggests taking the first letters.
The first letter of 'needed' is 'n'.
'ear'+'n'='EARN'
'to' acts as a link.
(Other definitions for earn that I've seen before include "net" , "Receive by effort" , "Make money" , "Make - merit" , "Merit through work or endeavour" .)