Why does my son's name come up on my icloud messages when I use my mac to send one? I am the only user signed up on my macbook.  My son's name comes up as the sender when I message someone via the mackbook.  Also, why aren't texts to my phone coming through on my macbook?
Thanks, everyone!
More info would be helpful. 

But assuming you are using the messages.app that comes with macOS. 

Open messages, go to the messages menu and select preferences > Accounts.

It is likely that the account that messages is using is your son's. You can uncheck his account (or just delete it) and add yours. And by "yours" I mean the same account you use on your iPhone/iPad which is usually the email address associated with your AppleID.