You finish in debt right at the start! (5)
I believe the answer is:
debut
'the start' is the definition.
(debut is a kind of start)
'you finish in debt' is the wordplay.
'finish' suggests the final letters.
'in' indicates putting letters inside.
The final letter of 'you' is 'u'.
'u' placed within 'debt' is 'DEBUT'.
'right at' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for debut that I've seen before include "The coming out of a society girl" , "Start -- launch" , "Beginning, first performance" , "First attempt" , "Introduction" .)