Why my new iPhone is showing only 2 bars of service

Bars are units measured in polite fiction.

Not a signal gage.

Numbers of bars shown can vary by device and by version.

Probably by carrier, too.

There is no agreed-upon standard for what a bar even measures.

Can you make calls, and can you receive calls?

If you can, then you have enough coverage.

To measure actual signal strength on an iPhone with Verizon, you can use Field Test Mode. This mode provides a more accurate reading in dBm than the standard signal bars.

By dialing *3001#12345# and pressing the call button, you can access Field Test Mode and view your RSRP (Reference Signal Received Power) value, which indicates signal strength in dBm.

The measurement will be a negative number. The closer to 0 dBm, the stronger (better) the signal.

Having only two bars of service indicates you are not in a strong, Verizon coverage area. Those bars will change as you move in and out of coverage areas.