To rename your workspace, open the workspace settings popup by clicking on the workspace name on your home page, or by clicking "Workspace Settings" from the workspace drop-down menu in a collection.
You can also click on the three dots next to your workspace name inside the panel on the left side of your screen to get to the workspace settings.
Click on the name of the workspace in the top left corner. A cursor will appear at the end. Type in the new name and hit Enter.
On a mobile device, swipe left and select the "..." icon to go to the workspace settings.
Tap on the field with the small pencil icon and enter the desired workspace name. To save the change, click on "Done" in the top right corner.