@Tonya22...are you able to try that sim in a different phone...to see if the problem is phone-related ?
Let us know if anything helps.
Check to see if your phone was added to be blacklisted, here: https://www.devicecheck.ca/check-status-device-canada/
Also, was your phone locked to its previous provider? If so, you will need to contact them to unlock it for you.
Maybe give the suggestions from this link a try.
Also try deleting all previous Carrier Profiles under Settings -> General -> Profiles.