Those with the least experience are, maybe, vainest (7)
I believe the answer is:
naivest
'those with the least experience' is the definition.
I can't judge whether this defines the answer.
'maybe vainest' is the wordplay.
'maybe' indicates anagramming the letters.
'vainest' is an anagram of 'NAIVEST'.
'are' acts as a link.
Can you help me to learn more?
(Other definitions for naivest that I've seen before include "Most open" , "very green" , "far from the most wise?" , "Most simple" , "Least sophisticated" .)