The most common and most likely answer to this crossword clue is the 7 letter word CADDIED
C
A
D
D
I
E
D
Buddy explains!
The straight part
We know that "went on a course to be helpful" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case went on a course to be helpful = caddied.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CADDIED mean?
CADDIED verb- To serve as a golf caddie.
- To serve as a caddy, carrying golf clubs etc.