Please find below a list of N adjectives which might be used to describe a person.
Positive
neat
neatest
neighborly
nice
nicer
nicest
nimble
nimbler
noble
nobler
noblest
Negative
naive
nastier
nastiest
nasty
naughtier
naughty
nauseating
negative
negligent
neurotic
noisy
nonsensical
nosy
nuts
nutty
Other
naked
nameless
napoleonic
nationalist
nationalistic
nearsighted
nebulous
needy
neoliberal
nerveless
nervous
neutral
neutralist
nonchalant
nonchurchgoing
noncommittal
nondescript
nonverbal
nonviolent
nostalgic
notorious
nude
There are many more lists of adjectives on this website. For more adjectives starting in N, see this post containing a large number of adjectives beginning with the letter N, some of which can be used for describing people.
novel