Click the Create DVD button along the bottom of the interface.
The "Choose an action" window will appear. Select one of the actions you want to do right after converting and click the Continue button.
Wait for the video to be converted.
Before clicking the Create DVD button you can set to turn off computer after the process is completed. Just go to Options... and make sure the appropriate box is checked.
After converting is completed click a small square button with the folder icon to open your output folder. There you can find VIDEO_TS folder with a converted DVD video.
If you want to burn a DVD disc you should set your input video as this VIDEO_TS folder.