You can delete viewports that you don't want or won't be using or keep the viewport and clear any changes made to it.
To clear a viewport:
1. Click the viewport that you want to clear.
2. Click the clear state button and click yes to confirm. This will remove all changes made to the viewport without removing it.
To delete the viewport altogether:
1. Click the viewport that you want to delete.
2. Click Delete viewport and click Yes to confirm.