Not really the person to take a hand (5)
I believe the answer is:
dummy
'hand' is the definition.
(I have seen 'exposed hand' mean 'dummy' so perhaps 'hand' could also mean 'dummy')
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for dummy that I've seen before include "Feign to pass" , "Model of a human being" , "Pacifier" , "who lays his cards on the table?" , "Clothes shop model" .)