First, check https://meshmap.net/ to see if anyone is around. If not, you can be the first (it just will be very quiet).
Next look for a device. I’m partial to this one: https://www.seeedstudio.com/SenseCAP-Card-Tracker-T1000-E-for-Meshtastic-p-5913.html - just make sure whatever you get it’s spec’ed for your region.
Then just download the Meshtastic app on your Android or iOS device and you’re set.
Here’s the archived version: https://archive.is/4jcSB