You can add columns and rows to Google Sheets by clicking on the "Insert" tab or right-clicking on the column or row where you want to add new content, then selecting the desired action from the menu. You can also add multiple columns or rows at once by highlighting the desired number of columns or rows and then selecting the "Insert" option. Additionally, Google Sheets has a mobile app that allows for easy addition of rows and columns on-the-go. Furthermore, Zapier is a no-code automation tool that enables users to automate workflows between different apps, including Google Sheets.