GL-X3000 AX Sim card help/recommendations

I just received my GL-X3000 today. I currently own a Verizon jetpack (4g/LTE) and an ATT netgear (4G/LTE) hotspot. These are both pay as you go sims/plans. Both need reactivation/pay for new service as we haven’t used them since September. We generally use these while traveling in our camper for 4-6 week trips once or twice a year. I wanted to ditch these devices and use the Spitz for our internet instead. My question or my request for recommendations is how to setup the Spitz with pay as you go or prepaid sims? I am open to ditching Verizon and go to Tmobile if needed since I understand Verizon is not supposed to work on this device? Will my current sims on 4G/LTE devices need to be upgraded to get 5G? Any recommendations when visiting the carrier stores on what to ask for or what is needed to get this working out the box with activated sims? I’m not completely tech ignorant but setting this up may be a challenge for me. We have a short trip at the end of Feb. to test this setup out for a long trip in Sept. Thanks in advance for any advice or recommendations.

Usually, you just need to insert the SIM and click “Auto Setup”. If it doesn’t connect, ask your operator for the APN and click “Manual Setup” to enter it.
Please refer to Cellular - GL.iNet Router Docs 4 (gl-inet.com)

Yes, it does not support Verizon SIM cards. If your Tmobile SIM card is an IoT card, it should work fine.

You may need to consult your operator on this issue and whether you need to change your SIM card.