Arrange everything you need (3)
I believe the answer is:
set
'arrange' is the definition.
(synonyms)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for set that I've seen before include "Scenery etc. for a drama" , "(Of the sun) drop below the horizon" , "Class" , "Solidify; group" , "See 16 Down" .)