Unable to make calls or receive texts on new iPhone due to missing phone number in SOS mode

Re: “I’m in SOS mode and cannot get out of it.”

SOS mode indicates that you are not connected to your carrier’s network or that there is a problem with your account on it. So of course you can’t make or receive regular phone calls.

The only ones you can make are emergency calls (e.g., 91/-type calls to get police, fire, or ambulance assistance). In some countries, carriers must put through those emergency calls even if you are not their customer and otherwise have no right to use their network.

To resolve the problem with your regular phone service, you need to contact your phone company (carrier).

If you believe that your problem is with your phone number, you might need to contact your carrier to get further support on the issue

Re: “I’m also only able to text other Apple users.”

Messages works both with SMS/MMS messages (a cell phone thing) and with iMessages (an Apple thing where messages go between Apple devices over the Internet).

The reason you can only text other Apple users is that without working cellular service, only iMessages are available.