For Dawn you’ll be going for bright colours, maybe with some fancy fabric. Look for shirts (preferably laced). Heck, if you can find a suitable dress and cut it into a tunic with enthusiastic scissors, that can also work. Colourful sashes made from whatever, trousers in some sort of neutral colours, and sturdy boots… It’s possible to tweak fairly basic kit towards any national brief.
Do you have the time/ability to do some basic sewing? Ribbons or braid in bright colours (which could also be looted from charity shop finds) attached somehow to the edges of a contrasting colour can also look good.
Do you have a House or colour scheme you want to stick to?
There’s a few other threads here which may be of use…