Should I get a new number if my iPhone is compromised?

Change the Passwords on your Apple ID and use a new Passcode for your iPhone. You should also change your Password on all sites that you have an account. Changing your phone number will not be necessary and will have no affect on an account the has been compromised. Review this document to avoid phishing attempts:

Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support

Your phone was not “hacked”. Why do you think it was?