Singer, very young, getting nothing right (5)
I believe the answer is:
tenor
'singer' is the definition.
(I know that tenor is a type of singer)
'very young getting nothing right' is the wordplay.
'very young' becomes 'ten' (I've seen this before).
'getting' means one lot of letters go next to another.
'nothing' becomes 'O' (looks like zero - 0).
'right' becomes 'r' (common abbreviation).
'ten'+'o'+'r'='TENOR'
(Other definitions for tenor that I've seen before include "Big bell" , "Highest male voice" , "Voice of Tamino" , "intent" , "exact words" .)