User account details – There is Account overview page which is provided be Mendix in order to maintain the Useraccount details such as User name and password.
Attach the account oveview page in the Navigation.
If your looking for other kind of customization make a page of your wish and attach to Navigation and run your project you will be able to see the pages.
Hope it help!
Take a look at Tarik Subashi’s MEndix 9.6 Building an e-Commerce Application course on Mendix in Udemy. He starts of with custom login and user account pages etc.