You can undo the action performed or the last few actions by pressing CTRL+Z.
You will need to click on the data option that is available on the top left, which provides you a drop-down menu, select the type of the data that you are using. It could be excel or anything. Once the data is selected you are allowed to edit the data before you load the same on to Power BI. It is good practice to edit the data by using the filter options or filtered data.
If you want to unleash your potential in this competitive field, please visit the Alteryx Training page for more information, where you can find the Alteryx Tutorial and Alteryx Interview Questions FAQ's and answers as well.
For more updates on the latest courses stay tuned to HKR Trainings.