A small shop that sells fashionable clothes, cosmetics etc.

One word substitute is Boutique.

Booth: a small temporary tent or structure at a market, fair, or exhibition, used for selling goods, providing information, or staging shows.
Stall: a stand, booth, or compartment for the sale of goods in a market or large covered area.
Boutique: a small shop selling fashionable clothes or accessories.
Store: a quantity or supply of something kept for use as needed.