How to enable Teams New meeting experience:

• Click on your avatar on the top right corner
• From  the drop down menu, click 'Check for updates.' It is always good to stay current and make sure you have the latest version. Please allow for 2-05 for Teams to check if there is an update
• Click on your avatar again
• Click on 'Settings'
• Under the category of 'Application,' click on the box next to 'Turn on new meeting experience...'
• Click on the X on the top right corner to close Settings
• Quit Teams (make sure it is still not running in the background). If unsure, reboot your computer.
• Open Teams