Go first; element (4)
I believe the answer is:
lead
I believe this clue is a double definition.
'go first' is the first definition.
(I've seen this in another clue)
'element' is the second definition.
(I know that lead is a superconducting element)
(Other definitions for lead that I've seen before include "Guide the heavy metal" , "Be ahead of - guide" , "Guide, direct" , "Actor playing the principal role" , "Church windows include this" .)