I am trying to open a new file in TurboTax Premier, but I cannot locate a 'file' button which I understand should appear. Can someone direct me how to do this?

There is a drop down menu at the top of the TurboTax application in a Dark Blue Ribbon, Select the File drop down and click on "New Tax Return"

There should be a choice you can find by clicking on the word "File" at the top left corner of the Turbo Tax screen.

Top Menu Bar -> File ->New Tax Return