Switch on led on slave board

I am completely new to arduino.
I would like to start playing with a beginning sketch, but really i do not know what to do.
Basic, i have two arduino uno boards and on each of them it is attached an ESP8266-01.
Each board has 3 push buttons and 3 leds.
What i want to do is to turn on led 1 on board 2 when i press button 1 on board 1.
The led should stay on as long as i keep pressed the button.
Also, if i press 2 or 3 buttons i want to see the corresponding led on.
Can you help me please.
Attached it is a general schematic.
I can wire it on breadboard and play with it if i have a startup or a piece of code.
Thank you very much.

ESP8266 Comunication.pdf (20.2 KB)

If you are new to Arduino, don't do anything complicated. Forget about board 2 for the moment. Do some examples from the Arduino IDE, or

Turn on led 1 on board 1 when i press button 1 on board 1.

Why are you wanting to do this?