A kick, after millions invested, to have a successful place (4,4)
I believe the answer is:
boom town
'a successful place' is the definition.
'boom town' can be an answer for 'place' (I have seen 'Place of prosperity' mean 'boom town' so perhaps 'place' could also mean 'boom town'). I'm not sure about the 'a successful' bit.
'a kick after millions invested to have' is the wordplay.
'a kick' becomes 'boot' ('boot' can be a synonym of 'kick').
'after millions' becomes 'm' (abbreviation. I am not sure about the 'after' bit.).
'invested' is an insertion indicator.
'to have' becomes 'own' (to have something is to own it).
'boot' going around 'm' is 'boomt'.
'boomt'+'own'='BOOM TOWN'
Can you help me to learn more?
(Other definitions for boom town that I've seen before include "Settlement enjoying sudden prosperity" , "Municipality enjoying sudden prosperity" , "Prosperous place" , "Urban area of rapid growth" , "Place of sudden prosperity" .)