As I think I've mentioned elsewhere, Random Nerd Tutorials is one of my favorite web sites as they have a lot of very useful instructional posts for a wide range of boards.
Here is one example that just came into my email...
randomnerdtutorials.com
This is an ESP32 board with 4G and there is a version that includes GPS as well. This board has a built in 18650 cell holder and a connector for a 6V solar cell charger. The A7670SA with GPS is about $55, and without GPS $49 on Aliexpress.
I would recommend those interested in learning programming various boards to have a look. They also have a number of free ebooks as well as some to buy, but all the info is on the site is you do not want to go the ebook way.
Here is one example that just came into my email...
Getting Started LILYGO TTGO T-A7670G ESP32 (4G, GPRS, and GPS) | Random Nerd Tutorials
Get started with ESP32 and the T-A7670G 4G/GPS/GPRS module. Use the LILYGO TTGO T-A7670G ESP32 board that combines the ESP32 chip, the A7670G (or A7670E, A7670SA) module.
randomnerdtutorials.com
I would recommend those interested in learning programming various boards to have a look. They also have a number of free ebooks as well as some to buy, but all the info is on the site is you do not want to go the ebook way.