Hey Ashleyb welcome to the forums.
According to the previews/video shown their will be many clothes stores that you can enter, and get clothes from hats, shirts, pants, and many different types of clothing/outfits are in the game that you can purchase. You can purchase clothes from shops, and vendors whenever you want too in the open world.
Also the clothes give you a buff if you wear a complete set like a pair of pants and shirt that go together. One outfit was the tourist outfit which if you wear, will increase you're pricing on clothes by 20 percent.
Here you see some clothes Wei is wearing