Change your Settings in Teams

To see or change your Teams software settings, click your profile picture at the top of the app. You can change your picture, status, themes, app settings, notifications, or language, access keyboard shortcuts, and more.

Update language, time, and date format

Click your profile picture at the top of the app, then select Settings > General and go to the Language section.

Selecting your preferred language and region also updates your time and date format.

Turn on high contrast mode

Click your profile picture at the top of the app, then select Settings > General. In the Theme section, click High contrast. You can also select the Dark or Default theme.

Set Teams to start automatically

Teams is set to automatically open and run in the background as soon as you start your device. If you close the app, it keeps running in the background.

You can change these settings anytime by clicking your profile picture at the top of the app, then selecting Settings > General. From the Application section, you can disable auto-start. You can also change your settings so the app won't run in the background or keep running after you close your window.

 

Source: https://support.office.com/en-us/article/change-settings-in-teams-b506e8f1-1a96-4cf1-8c6b-b6ed4f424bc7