WordNet sense 1 (a person who has suddenly risen to a higher economic status but has not gained social acceptance of others in that class):

arriviste, upstart, nouveau-riche

WordNet sense 2 (characteristic of someone who has risen economically or socially but lacks the social skills appropriate for this new position):

parvenue

WordNet sense 3 (making claim to or creating an appearance of (often undeserved) importance or distinction):

pretentious

WordNet sense 4 (not of long duration; having just (or relatively recently) come into being or been made or acquired or discovered):

new