Hi Adrija,
If you want to show different profile page for different user, then you can define role-based home page in navigation for each user role.
And if you want to show data of logged in user then give X path while retrieving as shown is image
You just need to make sure that all users of your system have a user role assigned that has a "Visible for" set on the page.
https://docs.mendix.com/refguide/page-properties/#361-visible-for
Have a look at the Module Security documentation. It explains in more detail how security works with user roles.
https://docs.mendix.com/refguide/module-security/
Good luck!