The Federal Information Worksheet will display and all the forms in your return will be listed on the left side. Simply select a form to open it.
To switch back to the interview, select the Step-by-Step icon in the upper right corner, or choose it from the View menu.
If you are using TurboTax Online, the QuickZoom function is not available to use. If you wanted to review other forms/schedules/worksheets, you would have to pay to print (not necessarily e-file yet): How do I print a copy of my TurboTax Online return before filing?
If you are using TurboTax Online and don't want to pay to print, you will only be able to preview Form 1040: How do I preview my TurboTax Online return before filing?
If you are using the desktop program, the zoom buttons are at the bottom right hand corner. If you are using the Online program, you are using your browser's (Chrome, Firefox, Safari, Edge, etc) zoom function which can be adjusted in the browser settings. @gjcamc2020