Sorry for such a basic question, but it is extremely frustrating when a tool you use all the time gets moved in a new software version and you cannot find it. Anyway, where is the header/footer tool/dialog box in Excel 365? I used to launch from an icon under Page Layout in officemac 2011.
Ok, I just found it under Page Setup! Now, is there a way to get a full size print preview (besides the tiny one in the print dialog box)?
Try going to the 'View' tab and select 'Page Layout' view on the left. That gives you a print preview. Under 'Page Break Preview' you can change the margins. Alternatively, you can select the scaling when you print.