I cannot make calls or access cellular data on my iPhone 5s IOS 12.5.5.How can I get rid of it?

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

Who is your cellular carrier.

Carriers have or are in the process of shutting down their 3G networks. Those that have done so require a device capable of VoLTE to use their network. That means an iPhone 6 or later.