Something like this.

https://heltec.org/project/wifi-lora-32-v3/

Using something like this for software.

https://meshtastic.org/

nostr:npub160t5zfxalddaccdc7xx30sentwa5lrr3rq4rtm38x99ynf8t0vwsvzyjc9 made a very solid recommendation. I run several of those.

This link below shows all of the currently supported devices.

I will go on a limb and assume you are in the US, in which case you would want a 915 mhz device. This also matters for upgrading the antenna if you go down that path. In other regions you would want a different frequency for the device.

https://meshtastic.org/docs/hardware/devices/

Unfortunately a lot of devices are out of stock and have been for a couple of months but apparently will be back in the second half of April. Average Gary's recommendation of the Heltec is good though, I have one. A good channel for Meshtastic stuff on Youtube is Ringway Manchester & another is Andy Kirby. 👍