Ff 14 clothing is obtained by participating in various activities in the game. There is no such thing as a shopping mall. If you want something special. When you see an activity, just pay attention to it (usually a festival or anniversary celebration).
Ff 14 is a good game, but it is not suitable for everyone. Ff 14 is a game with a fixed audience, just like FGO: the core audience of FGO is fate fans.