LoRa is short for Long Range. It's basically about providing a physical layer for networks over radio using spread spectrum modulation. It's got long range, even for fairly low-power devices, but also low bandwidth. Think IoT stuff. LoRaWAN is a layer above in the network stack (MAC) and runs on top of LoRa.

TNC is "terminal node controller". They're kinda sorta like modems for radios. KISS TNC is a particular protocol for communication between a radio and a TNC.