You cannot adjust the video position on the OpenAC-1, but you should be able to adjust the horizontal position on your VGA monitor. Check your monitor's menu settings.
To connect a terminal emulator, set jumpers A3 and A4 to the upper position, connect the Arduino Nano USB to your PC at 38400/8/N/1 with no flow control. Do not connect the power adapter, as the OpenAC-1 will be powered by USB.