You would be looking for something like this: https://en.wikipedia.org/wiki/LPWAN
I have never implemented the technology myself, but as I plan to run different sensors outdoors on my farm, I would be very interested in any answers that are more detailed and knowledgeable than mine.

Hi Anna, first of all thanks for your answer, looking at the article, there is not enough information, and looks like if you’ll need to use technology or networks from a third party, paying for the use.
One if my ideas was to connect all sensors in a single cabled network, and send data from all this network via NRLF24L01, and receive the data on another NRLF24L01 or something similar, another idea from my daughter just now, it’s to make again the local cabled connections, connect everything to an ESP32 and make it work on the Wi-Fi network created from the phone only, sharing the internet connection of your phone, I’ll try this possibility, to see the range, anyway let me know your thoughts, or your progress on this matter.
 
Regards:
JME

Hi again Anna, I recommend you to read the book Home Automation Using ESP8266 – 4th Edition, you’ll have a lot of ideas inside, I’m reading it nowadays, but carefully, not as in the past, and I’m getting a lot of answers, I can seriously recommend it to you

Hi Jose.
If you want to access a web server to check sensor readings like you would do on your local network, you can set your ESP32 as an access point instead of a wi-fi station. 
The ESP32 creates it’s own network and nearby devices (like your smartphone) can connect to it. You can see this unit of the course – it can be applied to any web server: https://rntlab.com/module-9/extra-access-point-ap-for-wi-fi-car-robot/
To exchange data between ESP32 boards, I would recommend: LoRa, ESP-NOW, or Wi-Fi.
I hope this helps.
Let me know if you need further help.
Regards,
Sara
 

Hi Sara, thanks for your valuable answer, I have it clear after read again Home Automation Using ESP8266 – 4th Edition, but just a concern, do you know how far away could I be with my iPhone from the ESP32 with no have the connection lost?

My project is to connect one of my RC boats, normally I use a Atmega 328P-PU based as onboard computer, the board, completely designed by myself has the processor, some buffers and so, and collects all signals of voltage and temperature from the boat model, at same time receives four servo channels  from the RC receiver and controls around 10 different outputs, mainly lights, but also radar motor at constant speed, controller of main motor enable, horn, and several other things, it’s able to generate alarms by low battery voltage, high temperature or emitter signal loss, previous versions, had a BLE HM-10 emitter sending internal data to my iPhone, and working well, bat the reach were few meters, I only can see the information being next to the boat, but not when navigating.
My current plan, it’s to use the same serial output previously used for Bluetooth, to concatenate the whole information in a single line, a single string, and send the info to an ESP32, on this ESP32, I could take more temperature readings or another kind of field data, and using it as a server, send the information, to any device having a browser on it, refreshing the info every 30 seconds or one minute.
Sorry for this long explanation

https://imgur.com/a/NamjmKk

Please, let me know if you’re able to see the pictures, thanks

Hi.
I now understand your project a bit better.
I don’t known the distance between the ESP32 boards or between the ESP32 server and your smartphone. It really depends on the environment. You have to test the distance and see what you get.
I couldn’t see the pictures.
To share pictures, you can post a link to imgur, a shared folder to google drive or dropbox.
Regards,
Sara