Well you’d start here
https://www.geeky-gadgets.com/how-use-meshtastic/
You self host a comms server, i use matrix, and that forwards the message to you.
If you’re directly tied to the SMS protocol you can setup a repeater here https://hackaday.com/2022/02/21/an-off-grid-makeshift-cell-network/
Then it’s meshtastic -> Matrix -> SMS gateway
Yes, however he toiled for a while on his own before release when he was still at university, that’s the time period I’m referencing.