Someone made a FaceTime call with the number

Seems to me your apple id is compromised and someone else is using it. Though I don't know why they'd call people in your contacts list. I'd suggest resetting your password ASAP!

I'm not sure there is a standard way. It certainly isn't easy to find by using the Contacts or the Facetime app. But, it can be done:

1. Send a text message to the specific number you want to Facetime call.
2. Open the conversation thread.
3. Click "Contact" in the top right.
4. Click the symbol for calling.
5. Choose "FaceTime Audio".