Have a go at tango, mostly unoccupied (7)
I believe the answer is:
attempt
'have a go at' is the definition.
(I've seen this in another clue)
'tango mostly unoccupied' is the wordplay.
'tango' becomes 'att' (I can't explain this - if you can you should believe this answer much more).
'mostly' means to remove the last letter (most but not all of the word).
'unoccupied' becomes 'empty' (similar in meaning).
'empty' with its last letter removed is 'empt'.
'att'+'empt'='ATTEMPT'
Can you help me to learn more?
(Other definitions for attempt that I've seen before include "Endeavor, try" , "Essay" , "Stab" , "Shot" , "Try to climb (a peak)" .)