Hi @Pattie22, sorry to hear about this. 
Based on the error message you receive, the device does not seem to be able to read your SIM card correctly and this can either be because the SIM card is defect, or there is something not working correctly with the device.
The best and easiest way to troubleshoot this is if you have another SIM card that you can mount in the device, or if you can borrow one from a colleague, friend or family member.
You can see how to remove and insert the SIM card on the link below.
https://support.sonymobile.com/global-en/xperial1/userguide/assembly-ss-content/
Let me know how it goes!
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