Start doing art with numbers, first of all (4)
I believe the answer is:
dawn
'start' is the definition.
(the dawn of something is its origin)
'doing art with numbers first of all' is the wordplay.
'first of all' says to take the initial letters.
The initial letters of 'doing art with numbers' is 'DAWN'.
(Other definitions for dawn that I've seen before include "Begin to appear" , "Light in East" , "Early morning sing-song?" , "Sunrise" , "Cockcrow" .)