Teams Breakout Rooms
Meeting Organizers can create Breakout Rooms within Teams.
As the Meeting Organizer, select the Breakout rooms option in the top bar

You will see options for
The number of rooms you want to create
The option to assign participants automatically or manually

You will then be able to manage the rooms on the right-side menu

You can create, delete, rename rooms.
When you are ready for participants to use the rooms, choose Start Rooms

Assign or Switch Rooms

Send an Announcement to All Groups

Resources
https://www.jumpto365.com/blog/how-to-use-breakout-rooms-in-microsoft-teams