This is the way of implementing the following tutorial in C. (https://services.suvink.me/opengl-c)

drawing.c

#include<stdio.h> 
#include <OpenGL/gl.h>
#include <GLUT/glut.h>

void myInit (void){
    glClearColor(1.0, 1.0, 0.0, 1.0); 
    glColor3f(0.2, 0.5, 0.4);
    glPointSize(10.0);
    gluOrtho2D(0, 500, 0, 500); 
}

void display(void){
    glClear(GL_COLOR_BUFFER_BIT);

    glBegin(GL_POINTS); 
    glVertex2f(100, 100);
    glVertex2f(300, 200);
    glEnd(); 

    glBegin( GL_QUADS );
    glVertex2f( 100.0, 100.0 );
    glVertex2f( 300.0, 100.0 );
    glVertex2f( 300.0, 200.0 );
    glVertex2f( 100.0, 200.0 );
    glEnd(); 

    glBegin(  GL_TRIANGLE_STRIP );
    glVertex2f( 100.0, 210.0 );
    glVertex2f( 300.0, 210.0 );
    glVertex2f( 300.0, 310.0 );
    glEnd(); 

    glFlush(); 
}
  
int main (int argc, char** argv) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);  

    glutInitWindowSize(500, 500); 
    glutInitWindowPosition(100, 100); 

    glutCreateWindow("Python Code 1"); 

    myInit();

    glutDisplayFunc(display); 
    glutMainLoop(); 
}

/*

Run this with following format
gcc filename.c -o filename -framework OpenGL -framework GLUT

*/