No worries! If you’re starting out you can’t go wrong with a T1000-E. It’s water resistant, has GPS built-in, and ties everything together in a neat package for ~$35. There are plenty of other nodes out there but it’s more of a build your own kit situation. If you’re into microcontroller programming and stuff like arduino/RP/etc then Heltec v3 Lora boards are good tinker hardware.

We also have a community here on mander for meshtastic.

Yes! If you leave the default channel enabled it will join the public meshtastic network. But you can run eight channels at once, and the others can have different encryption keys.

The default setting is also to forward any received packets to the mesh, even ones it can’t decrypt.

For a good compromise, use Meshtastic. Long-range radio mesh network for texting that phones can use instead of cell networks.