Terry gets a lot of phone calls from local numbers he doesn't recognize. Leo says that's called "Neighbor Spoofing" and it's designed to get you to answer your phone because the caller ID shows a local number. So don't answer any phone call you don't recognize. If it's important, they'll leave a message. You can always call back.
Can I respond to text messages with VOIP? Leo says you can partially. If you're using an app like WhatsApp, you can as long as the other side uses it. But if it's a "text subscribe to [enter number here]." It won't. VOIP doesn't support that.