Unfortunately my job requires me to look at an excel worksheet for 99% of the day so I'm quite accustomed to it.

There are several ways to do it -

To create an new sheet on an existing workbook click the "insert" tab at the top of the page and then click "worksheet"

An alternative way is to right click the sheet tab at the bottom of the page and then click inset then click worksheet.

If you want a fresh new workbook there should be an icon in the top left that looks like a sheet of paper - click that.

Or you go file>new> etc..

Andy