Why won’t my phone connect to my network provider?

For the past few weeks, I’ve been having issues with my phone connecting to my provider. I’ve checked with Verizon and there’s no issue there. I’ve tried master resetting multiple times, I’ve taken the SIM card out multiple times. I’m trying to update my phone to see if that’ll help, but it doesn’t. I commect To WiFi and after trying to verify the update, it tells me I’m not connected to the internet, but i have WiFi. I don’t know what else to do.