Serial Communication Btwn 2 Arduinos

Using Arduino Programming Questions
1

Hi, everyone. I'm trying to learn how to communicate serially between 2 Arduinos. I can send and receive PWM values, but I have not figured out how to send strings. I have 2 Arduino Mega 2560s. I want to be able to see the full character string in the serial monitor of Arduino1, but no matter what character string I send, I get only the last one to print to the monitor. How do I get the entire string to print?

Connections:
Arduino1 GND --> Arduino2 GND
Arduino1 rx3 --> Arduino2 tx3
Arduino1 tx3 --> Arduino2 rx3
Arduino1 --> Laptop via USB

Arduino1 (Base) Code:

void setup(){
  Serial.begin(9600);
  Serial3.begin(9600);
}

void loop(){
  if (Serial3.available()){
    char x = Serial3.read();
    Serial.print(x);
  }
}

Arduino2 (Remote) Code...ignore the commented out code:

void setup(){
  Serial.begin(9600);
  Serial3.begin(9600);
  
  //Serial2.begin(4800);
  //Serial2.write('!GPS');
}

void loop(){
    /*if(Serial2.available()){
    char x = Serial2.read();
    Serial3.write(x);
  }*/
  
  char x = 'ABCDEFG';
  Serial3.write(x);
}
2

char x = 'ABCDEFG';

is wrong

char x[] = "ABCDEFG";
or
char x[8] = "ABCDEFG"; // 8 chars from 0 to 7, including a terminating \0.

for (int i =0; i< strlen(x); i++) Serial.print(x*);*
hope this helps..

3

char x = 'ABCDEFG';

Which SINGLE key did you press to assign this value to this character?