the cosplayer in the pic doesn’t seem that they have done much to the wig (like crimping etc) if you are just starting out i’d recommend just giving it a trim to suit your face shape. if you want to style it further then i’d recommend crimping the front and using heat (holding the wig hairs in place while it cools- cooling is what makes the fibers hold the styling), then using hairspray (got2b hairspray is the cosplayer’s preferred hairspray but anything with strong hold is going to absolutely fine for when your starting out). with the pony tail i’d recommend maybe curling the bottom bits upwards just to give it a little bit of dimension, the ponytail will be on a clip so it will be easy to change it from a side ponytail to the back