iPhone FaceTime audio and texting

Last night I got a strange text from my son at 3 o’clock in the morning. When I called him the next morning to ask him what that was about he said he never text me. I sent him a picture of the text and he said it wasn’t on his phone. I called him later using FaceTime audio he didn’t answer and then I got a phone call from his number when I answered it was a strange man. He said this was his number and why was I calling him. I believe he hacked into some thing. Possibly my Apple ID? Has anyone had this happen to them before.? If so how do I correct??