As someone who has made Pyrrha, that's not really a beginner build. Ponytail wigs, corsetry, leg armor mounts with no distinct closures... it's tough!
I've seen commercial patterns out there that are almost exactly identical to Yang's jacket, so that's probably the simplest of the girls you listed.
If you want to go suuuuper easy, workout!Nora
would be a piece of cake! You could also probably thrift dresses that are really similar to any one of those girls' outfits from the Dance Dance Infiltration episode prom episode.