You can send text messages to Facebook friends as long as your friend has shared their phone number with you (through Facebook). You can also instant message Facebook contacts, through the same messaging interface on the phone. While writing your message, use the switch button (looks like two arrows) to choose between text messaging and Facebook messaging.
When you receive a text message from another person, can you send a reply to it? What error message appears if the reply fails to send?
Have you tried turning off Wi-Fi Calling? (Use the Wi-Fi Calling app to do this; it is not in the phone's settings.)
Is Facebook the only option with these phones as far as our contact information goes? The error message is this: "The message you sent to 1-###-###-#### wasn't delivered. Make sure the address is correct, and then try sending the message again."
These are our first smart phones, so we are very new to all of this. I have not turned off wi-fi calling and do not know how to. Is this a free app we need to download?
No, you can also have contacts in your Microsoft account (usually Hotmail.com, Outlook.com, or live.com), or in Google Mail (usually gmail.com). And in some others, like LinkedIn, Twitter. To add accounts or see which ones you've already added, swipe to the left on the start screen, go to settings, then email+accounts.
Wi-Fi Calling is preinstalled by T-Mobile on that device. It allows phone calls and text messages to go through your home's wireless network rather than through the T-Mobile cellular network. However, it is pretty buggy, which is why I'd recommend turning it off. There is a light blue tile for it on your start screen, or if you've removed that, you can still find it in the apps list under W (swipe to the left from the start screen).
Oh one other thing -- if your phone numbers are being ported over from your previous carrier, you might have some trouble with text messaging for the first few days. At least that was my experience when I ported over from Verizon Wireless to T-Mobile a couple years ago. Windows Phone was my first smart phone, too! (Great choice!!)
We want your text messaging working! The tips sneakymoose provided are excellent, are you still getting the error message on your outgoing messages? The 1 in front of the numbers shouldn't make a difference, a quick test you can try is to manually type in a phone number when sending a message instead of selecting from your contact list, this will help determine if it's something to do with how the numbers are programmed, or something else!