Opening a shop? (6)
I believe the answer is:
outlet
This clue is a double definition.
'opening' is the first definition.
(outlet is a kind of opening)
'a shop?' is the second definition.
(shop is a kind of outlet)
(Other definitions for outlet that I've seen before include "Passage through which things can escape" , "Shop (retail)" , "Retail point" , "Means or occasion for giving vent to feelings" , "Maths relationship" .)