Hi @genec.tcqyix and welcome to the Community!
The x indicates your phone is not receiving data from the cell tower it is connected to. Cell data even on a talk & text only plan is required for text messaging when away from WiFi. You do not need to pay for cell data used for text messaging but the phone must have access to it.
As starting points, would you be comfortable sharing a zip code (nothing more), so we might look at coverage in your area? Would you also let us know which SIM type your phone is provisioned with. Here’s how to tell: