Coach can be used to transport people (5)
I believe the answer is:
train
'coach' is the definition.
(both can mean to instruct a sportsperson)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for train that I've seen before include "School, educate" , "Number of animals moving in a line, like camels" , "held up in union action?" , "tutor" , "become physically fit" .)