It's still unclear exactly what you need. Do you want to know how to handle login? How to store user data? How to ensure only a user (or admin) can view the user's data (i.e. authorization)? Something else? If you don't know what help you need, no one else can tell you.For examples: x10 we have member panels, we log in, we see the forum threads.
Or like you make a account for an online game, you log in, and your accessing pages only signed in member would view.