iPhone data transfer from iPhone 6 to iPhone SE 2020.

I am transferring my data from an iPhone 6 to an SE 2020. The transfer seemed to go OK but I have no wireless service. My iPad, computer, and smart TV all work fine. I cannot make or receive phone calls or receive or send email. The phone just says no service. I tried removing the network data and reinstalling it, and I made sure that the router and the password were correct. Being 83 years old it’s a a little tough dealing with this stuff. The information was a little vague on when to install the SIM chip so perhaps I didn’t do it correctly. All comments are welcome. Thank you.