Find one must take a right turn first (5)
I believe the answer is:
trace
'find' is the definition.
(thesaurus)
'one must take a right turn first' is the wordplay.
'one must take' becomes 'ace' (I can't justify this - if you can you should believe this answer much more).
'a right' becomes 'rt'.
'turn' shows that the letters should be reversed in order.
'first' says to put letters next to each other.
'rt' reversed gives 'tr'.
'ace' put after 'tr' is 'TRACE'.
Can you help me to learn more?
(Other definitions for trace that I've seen before include "Evidence" , "Discover whereabouts" , "Describe, small quantity" , "strap for drawing carriage" , "plan" .)