Why is my husband's phone getting my texts, resent phone calls and emails??

He needs to go to Settings, tap on his name at the top, then scroll down and sign out. He can then sign in to his own Apple ID if he has one, or create one if he doesn’t→https://appleid.apple.com/account. He can also create it on the phone itself.

Once he has his own Apple ID you can set up Family Sharing to share purchases of apps and music, and share some content such as calendars and photos. See→What is Family Sharing? - Apple Support

The same way you setup your Apple ID and password. But it would his own email address, and password.

Because he is sharing an Apple ID with you. Apple IDs are intended to be personal, and shouldn’t be shared any more than you would share a toothbrush.