Have some of the drink I'd brought back first (3,2)
I believe the answer is:
dig in
'have some of the' is the definition.
I can't judge whether this definition defines the answer.
'drink i'd brought back first' is the wordplay.
'drink' becomes 'gin' (gin is a kind of drink).
'brought back' says the letters should be written backwards.
'first' is a charade indicator (letters next to each other).
'id' reversed gives 'di'.
'gin' after 'di' is 'DIG IN'.
Can you help me to learn more?
(Other definitions for dig in that I've seen before include "Start to eat" , "Begin eating heartily" , "Enjoy the food" , "Start to scoff" , "protect himself" .)