Samsung Note 20 Ultra 5G

I have tried contacting Xfinity Mobile on Messenger, but they can't answer my question and keep giving me the run-around about making sure I'm on the 3rd generation plan but couldn't explain to me what that was. I kept checking the Xfinity Mobile website, but there is nothing there about a 3rd generatin plan. Only thing I need to know is when I get my 5G phone tomorrow, will I automatically be connected to the 5G network? I'm already on the Unlimited plan for $45.00/month, so does that qualify? The phone was ordered from Xfinity Mobile.

Thanks in advance for any and all information.

Stay safe.

Also, I don't know if anyone can answer this, but how can spammers call me using my own phone number and name? I was shocked when a call came through and it displayed my phone # and full name. I've blocked it, but how did that happen?