I don't care what kind, just something simple. I can't get any of the hair to add, so I think I need to buy some.

The wardrobe is a bit of a mess right now but despite it saying you can not use any hair, all of the hairs listed here should appear on site when saved. You can also get hair by

1. Buying wigs. these are normal wearables just like the top you are wearing, to start with there should be some cheap ones for sale in the lower half of the grooming parlor's selection.
2. Redeeming delish or hair coupon hairs (faaaaar more expensive, not resellable)

So you should be able to open up the new wardrobe and check out your items here. https://new.subeta.net/wardrobe/items The hair salon right now has been a bit finicky with everything being updated.

You will also be able to access a drop down to select All items which showcases things you do not own. (You are also able to select to view Non-CW items and CW items as well. Plus the different layers, like head for wigs!) Some of these items will show a 'Buy Now' (the system is still being worked on so not everything you don't own will show with a buy button) or you can hover over it & grab the name & search it in the shop search!

Thank you for the help, I figured it out!

Yay! :)