Unimportant employee — good company at first (3)
I believe the answer is:
cog
'unimportant employee' is the definition.
'cog' can be an answer for 'employee' (I have seen 'minor employee' mean 'cog' so perhaps 'employee' could also mean 'cog'). I'm not sure about the 'unimportant' bit.
'good company at first' is the wordplay.
'good' becomes 'g' (abbreviation).
'company' becomes 'co' (abbreviation).
'at first' says to put letters next to each other.
'g' after 'co' is 'COG'.
Can you help me to learn more?
(Other definitions for cog that I've seen before include "Tooth on the edge of wheel" , "Projection on a toothed wheel" , "that engages with others in revolution" , "Little gearwheel" , "one engaged in revolutionary activity" .)