To begin with, keep hugging a celebrity (3,1,5)
I believe the answer is:
for a start
'to begin with' is the definition.
(I've seen this before)
'keep hugging a celebrity' is the wordplay.
'keep' becomes 'fort' (I've seen this before**).
'hugging' indicates putting letters inside.
'celebrity' becomes 'star' (I've seen this before).
'a'+'star'='astar'
'fort' placed around 'astar' is 'FOR A START'.
(Other definitions for for a start that I've seen before include "To begin with" , "In the first place" , "initially" .)