Meshtastic runs on a lot of boards. For a first node there are really three families, and the right one depends on whether it's going in your pocket, on your dash, or on a roof.
The one spec that matters
Buy the 915 MHz version. In the US, Meshtastic runs in the 902-928 MHz ISM band. A 868 MHz (EU) or 433 MHz board will not talk to anyone here and is illegal to transmit with.
Three good answers
Heltec V3 - the cheap start
ESP32, small OLED screen, USB-C, around $20-25. Great to learn on. Two catches: the screen and the ESP32 make it power-hungry, so it's poor on a battery, and the tiny stock antenna is barely an antenna. Perfect on a desk plugged into USB.
LILYGO T-Beam - the mobile node
ESP32 with built-in GPS and an 18650 battery holder. This is the one for the truck or the backpack: it knows where it is, so your position shows up on everyone's map. The "T-Beam Supreme" adds a better GPS and screen. Still ESP32, so still thirsty.
RAK WisBlock 4631 - the solar node
Nordic nRF52840 instead of ESP32, which means roughly a fifth of the idle current. This is the board people put on rooftops with a small solar panel because it just doesn't die. Modular (you add GPS, sensors), no screen by default, a little more expensive. If your goal is a permanent node for your area, skip straight here.
Also worth knowing
- LILYGO T-Echo - nRF52 + e-paper + GPS in a case. Excellent handheld, pricier.
- Seeed T1000-E / SenseCAP Card Tracker - credit-card sized, sealed, GPS. Fun, hard to expand.
- Station G2 - high-power (~35 dBm) ESP32 node for the truly ambitious. Not a first board.
Antenna
Whatever you buy, budget for a real 915 MHz antenna. The 2-3 dBi stubby that ships with most boards is fine to prove it works; a proper 5-6 dBi omni on a short cable is where the range comes from. Never transmit with no antenna attached - it can damage the radio.
Pocket: T-Echo or T1000-E. Desk: Heltec. Dash: T-Beam. Roof: RAK. And 915 MHz, every time.