Is there any tutorial I can reference to see how I can use the editor for editing the actual UI of the website?

Is there any tutorial I can reference to see how I can use the editor for editing the actual UI of the website?

Example I want to know how to do following -
- modify the navigation links in header/footer
- customize the page to suit my exact needs
- in the desktop, view customizes the "category" navigation from a click based drop down to some other behavior/design.