can I check if why my motor isn't working?
Well, your wiring is OK, but I think the

'digitalWrite(enB, HIGH);

in the loop() code is causing your problem.  You don't want to try to use the same pin for both digital and analog functions.

I wired up a Uno here with your setup and a L298N, and got a motor to run fine with the following sketch that doesn't use the loop() at all - it does everything in setup().

char data = 0;
int enB = 9;
int InC = 8;
int InD = 7;


void setup()
{
    Serial.begin(9600);
    Serial.println("Motor test !");
    pinMode(enB, OUTPUT);
    pinMode(InC, OUTPUT);
    pinMode(InD, OUTPUT);

    Serial.println("motor should start moving now !");
    digitalWrite(InC, HIGH);
    digitalWrite(InD, LOW);
    //digitalWrite(enB, HIGH);

    for (size_t i = 0; i &lt; 10; i++)
    {
        analogWrite(enB, 20*i);
        Serial.print("motor speed = "); Serial.println(20 * i);
        delay(2000);
    }

    Serial.println("quitting!");
    while (true)
    {

    }

}


void loop()
{
    //Serial.println("Entered loop, should start moving now !");
    //digitalWrite(InC, HIGH);
    //digitalWrite(InD, LOW);
    //digitalWrite(enB, HIGH);
    //analogWrite(enB, 255);
}


If you can't get your motor working with the above program, then you most likely have a connection or power supply or component problem that you'll need to troubleshoot.

Hope this helps,

Frank