Old Norse refers to the language. Norse refers to the people.

"Thank you" in Old Norse, the language of the Vikings, is "takk."

No, the language of the Normans was French. Their ancestors spoke Norse.

Eric the Red was a Norse explorer, and he is believed to have spoken Old Norse, which was the language of the Vikings. Old Norse is an ancient North Germanic language that was commonly spoken in Scandinavia during the Viking Age.

Swedish is a derivative of Old Norse, and their word for "Wolf" is "Ulv". Old Norse, as a language, seems to be extinct.