One to many bidirectional communication

[ADemo21]

I have not found the solution of my problem but... my english is poor and, may be, the solution exist.
I wan't to do this project using Arduino cards (with ESP8266) and esp32
=> a program on a PC communicates via usb with one main esp32 (say card A) send message and received message via Serial.read and Serial.print
=> the card A must communicate with a card B via wifi : A send message to B AND receive message from B
=> the card A must communicate with a card C via wifi : A send message to C AND receive message from C
and so one... on the card B, C, D... I have sensor or motor
I don't understand how I can assume this bidirectional communications ?
I suppose A is an accès point server ; must it also be a station (I think yes not sure)
And for B, C, D... can they also be AP + station ??? I try with B station but I can not seem to have bidirectional communication.
My questions are :
- how can this work ?
- if it can work, how many cards can communicates with A

Thank you for your answer and sorry for my very bad english !