Tourist needs face mask going round city centre (7)
I believe the answer is:
visitor
'tourist' is the definition.
(eg a visitor to another country)
'face mask going round city centre' is the wordplay.
'face mask' becomes 'visor' (mask for one's face).
'going round' indicates putting letters inside (some letters go around others).
'city centre' becomes 'it' (centre of the word 'city').
'visor' going around 'it' is 'VISITOR'.
'needs' is the link.
(Other definitions for visitor that I've seen before include "Person turning up" , "One coming calling" , "One coming to call" , "Company" , "who might stay?" .)