Star tours racecourse, one somewhere in Canada (4,6)
I believe the answer is:
nova scotia
'in canada' is the definition.
('Nova Scotia' is part of 'canada')
'star tours racecourse one' is the wordplay.
'star' becomes 'nova' (nova is a kind of star).
'tours' means one lot of letters goes inside another (tour can mean to go around).
'racecourse' becomes 'ascot' (British racecourse).
'one' becomes 'i' (Roman numeral).
'ascot'+'i'='ascoti'
'nova' enclosing 'ascoti' is 'NOVA SCOTIA'.
'somewhere' acts as a link.
This may not be correct. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for nova scotia that I've seen before include "Canadian province" , "Canadian peninsula" , "Atlantic region" .)