[header] How to add columns on google sheets on pc or mac [title] Go to https: // sheets. Google.com in a web browser. [step] This will bring up a list of spreadsheets you've worked on recently. [substeps] If you're not already signed in to your google account, you'll be prompted to do so now. 
[title] Open the spreadsheet you want to edit. [step] There are three ways to do this : [substeps] If the file is already in your google drive, you'll see it in the file list.