After entering the game, press esc to look at the map. There is something in the shape of a small dress. Drive there (there is a clothing store) and walk to the door with the yellow triangle symbol. Go in and buy clothes, and then help you put them on automatically. Back to CJ's hometown, there will also be a door with a yellow triangle symbol upstairs. You can go to the red circle to change clothes after you go in. Remember that the space bar means confirmation, and the Enter key means exit.