Switching from AT&T post-paid plan to pre-paid: Is it possible, any gotchas?

[testcase]

I'll be dumping ATT when my "contract" expires later this year. Apparently, said "contract" does NOT apply or bind ATT and, they can change agreed upon terms at their leisure. The final straw is that, even though my iPhone6s+ shows I have 2~4 dots of LTE service ( AND sometimes also have a WiFi connection) I'm told I'm NOT connected to the internet. :villagers:

Diagnostics run by ATT & Apple claim my iPhone is "OK".