Dan’s off to the beach (4)
I believe the answer is:
sand
'the beach' is the definition.
'dan's off' is the wordplay.
'off' is an anagram indicator.
'dans' with letters rearranged gives 'SAND'.
'to' is the link.
(Other definitions for sand that I've seen before include "Very tiny grains of rock" , "Grains by the sea" , "Smooth with abrasive paper" , "George - - (French authoress)" , "Fine stone particles" .)