Phone won’t receive calls or text messages

Try first to optimize the range of the mobile network, see this Apple article:

If you see No Service or Searching on your iPhone or iPad

If you see No Service or Searching on your iPhone or iPad - Apple Support

See this Apple articles below:

If you can't make or receive calls on your iPhone

If you can't make or receive calls on your iPhone - Apple Support

If you can't send or receive messages on your iPhone, iPad, or iPod touch

If you can't send or receive messages on your iPhone, iPad, or iPod touch - Apple Support

Read again -> Related Article -> If you can't activate your iPhone

If you still can't activate your iPhone, contact Apple Support.