Hi Gillian. Welcome to justanswer.
The printer will automatically print on only one side until or unless you put back the same printed paper backwards into it.
Can you tell me which printer are you using?
Which operating system is there on your computer? Windows or Mac OS?
Once you click this link below(CLICK HERE)A file will automatically get downloaded. Check your download section, a file named ELSINORE.SCREENCONNECT will be present. Just open that file so that I can connect to your computer.
No problem, I will see that. Please start the remote desktop session by downloading and running the file from the link which I provided above
Start the session and I will show you how you can change that setting
Gillian are you starting the session or should I guide you through this request only?