The rabbit hole of Meshtastic/LoRa

Ok im new to Meshtastic and LoRa and want to start the journey. I have spent the last few days looking around the interwebs at all kinds of information about LoRa, Meshtastic, LoRaWAN and MQTT. My question is i would like to have a few nodes put up in my area that will obviously be a small mesh network. I would also like to put some in a neigbooring town that i work in. I want to know will they be able to communicate to each other? Total distance would be less than 20 miles. And i dont have the ability to put a node between them. Or would it be better to make a node a gateway to MQTT? Then would i need another gateway node in my home area to communicate between the mesh networks? And then on the same line can i use a raspberry pi to connect with Meshtastic like i would with a T-Beam? Or is this a LoRaWAN only kind of thing? And can you use LoRaWAN to connect with MQTT to talk to Meshtastic devices? Whats the range limitations to Meahtastic devices? I know this is a line of sight kind of thing and i live in a mostly flat area. I am wanting to know if i can use Meshtastic kind of like amature radio and “talk”/text around the world. I feel like this has many possibilities and before i invest in this heavily i want to know it limitations or is it limitless? Any direction you can point in would be greatly appreciated.

Based on the wrecked gotenna, all you can get is line of sight