After logging in, there is only an image, but no sound.

Hello,

It looks like the browser joined the Teams meeting with audio blocked or with No audio selected on the pre-join screen.

Close the meeting tab. Open the meeting link again. When the pre-join page appears, click the lock or camera icon next to the address bar. Set Microphone to Allow. Set Camera to Allow. If you see Sound or Automatic sound permission, set it to Allow or Automatic. Close that small permissions panel.

Back on the pre-join page, dismiss the banner that says Continue without enabling audio or video. Make sure Computer audio is selected. Click the small gear icon on the pre-join screen. In Speaker, pick the speakers you normally use on Windows. Use the Test button if it is available to confirm you hear the test tone. Leave Microphone on the correct device as well. Finally click Join now.

If this works, great. If not, tell me which browser you are using and whether the gear icon shows any speakers in the list so I can give you the next step.

You were trying to install Teams on an older Windows 10 computer with Windows version 10.0.18362.

Teams is not supported on this old Windows version. Teams requires now Windows 10 version 10.0.19041 or higher.

https://learn.microsoft.com/en-us/microsoftteams/teams-client-system-requirements

You should be able to run Teams for Web version in a browser.

https://teams.live.com/v2/

However, even in a browser there might be limitations if an older browser version is used. The latest Edge or Chrome browsers cannot be installed on this old Windows system.

My personal experience is that it is best to use the latest Firefox browser.