How can I get rid of this window (Xbox)?

Help

Red B button should help.

Rebooted the Xbox thank you

Just choose a game mode? It says choose a game mode, depending on what you want to play! And if you mean that you want to close Fortnite, then press the home button and when you are on fortnite with the pointer go to options and close.

He meant this little menu to the left of the screen 🤦♂️

Oh, he should have written with me. I was already wondering.

You can turn this off in the success tab of the Xbox quick menu.

The option should be called Enable / Disable Success Tracking.

Hope I could help.