starting new website

Hello .
I am a programmer and I live in Iran.
So far, I have had no site for international sales and only local sales.
I want to set up a website for a virtual number. If any of my friends have any suggestions, please let me know

You should be following a giant competitor then you can proceed well. Big names are Vonage, Toll Free Number, Real PBX and many more. You can have a idea by visiting their websites