*Unrelated to original question, merely FYI*
If FB was installed on your phone when you bought it and you didn't clear everything, I'm concerned the phone wasn't wiped back to factory settings. It certainly sounds like it wasn't. If you get a 2nd hand phone you should always wipe it and start from scratch. Otherwise, anything could be installed, including apps that report passwords, emails etc. If you haven't installed 100% of what is installed, you are open to large security risk.
Also, I'm going to ignore your "Luddite" moniker, and say you should use Whatsapp. The fact that you know about it means you are not a luddite. I have recently engaged my 69 year old father on Whatsapp so there is hope for anyone.