Once you finish the 1st part of the tutorial, you'll be able to choose your player name. If you want to change your name again, you have access to 1 free additional name change. To do that, please follow the guide below:
Click on Settingsin the top right corner of the home screen.
Find the section Profile Name and click on the blue Change button.
Type your new name in the box and click on Confirm.
IMPORTANT: Please note, that every player is granted only ONE free name change.