I would like open a shop for hair accessories,what i should do first?

First make sure you can sell. Make your designs, sell them at artisan fairs, on eBay, and make a website. When you start to do well you may be able to open your own shop, although most designers have to get others to carry their lines before they have their own store.

P.S. Good luck! Maybe you could post a picture of some of your accessories, I'd love to see them.