Having set up gear, learner cooked, entertaining new sweetheart (10)
I believe the answer is:
girlfriend
'sweetheart' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for girlfriend that I've seen before include "date" , "Sweetheart" , "Female squeeze" , "Female companion" .)