In the conditional you must use "==" to compare.

if( shape == 1) {...}

Thank you! Now that part works and I'm receiving a different error.

"The field component.x is not visible."

1. class Ball {
     float x, y;
     float xSpeed, ySpeed;
     float radius = random(5, 25);
     boolean collision = false;
   
   
     Ball() {
       init();
     }
   
     void init() {
       xSpeed = random(-1.1, 1.1);
       ySpeed = random(1.5);
       x = random(width);
       y = random(-200, -50);
     }
   
     void update() {
       x += xSpeed;
       y += ySpeed;
   
       if (abs(xSpeed) > 3)
         xSpeed *= 0.9;
       if (abs(ySpeed) > 3)
         ySpeed *= 0.9;
   
       if (x < radius) {
         x = radius;
         xSpeed = -xSpeed;
       }
       if (x > width - radius) {
         x = width - radius;
         xSpeed = -xSpeed;
       }
       if (y < 0 + radius) {
         y = 0 + radius;
         ySpeed = -ySpeed;
       }
       if (y>height-radius) {
         y=height-radius;
         ySpeed = -ySpeed;
       }
     }
   
     void display() {
       if (!collision) {
   
         //fill(0, 255, 0, 128);
         changeShape();
         //fill(random(255), random(255), random(255), 128);
       }
       else {
         fill(255, 0, 0);
       }
   
   //    ellipse(x, y, radius*2, radius*2);
     }
   
     void run() {
       update();
       display();
     }
   }
   
   void changeShape() {
     int Shape = int(random(1, 6));
    
     if (Shape == 1) {
       rect(x, y, radius*2, radius*2);
     }
     if (Shape == 2) {
       triangle(x+30, y+75, x+58, y+20, x+86, y+75);
     }
     if (Shape == 3) {
       ellipse(x, y, radius*2, radius*2);
     }
     if (Shape == 4) {
       fill(random(255), 0, 0, 128);
       rect(x, y, radius*2, radius*2);
     }
     if (Shape == 5) {
       fill(0, random(255), 0, 128);
       triangle(x+30, y+75, x+58, y+20, x+86, y+75);
     }
     if (Shape == 6) {
       fill(0, 0, random(255), 128);
       ellipse(x, y, radius*2, radius*2);
     }
   }
   
   

I tried renaming it the following and receive yet another error.

Cannot make a static reference to the non-static field Ball.x

1. void changeShape() {
     int Shape = int(random(1, 6));
    
     if (Shape == 1) {
       rect(Ball.x, Ball.y, Ball.radius*2, Ball.radius*2);
     }
   

" The field component.x is not visible."
It is a subtle variant of "no variable of this name can be found". It found an upper-level variable but fortunately (because it is not the one you expect), it cannot be used...

" Cannot make a static reference to the non-static field Ball.x"
Indeed. I don't know if you fully grasped the concept of OOP. You declared a class, which is a kind of blueprint: in general, you cannot use the fields and methods (variables and functions declared in the class) directly. You have to make an instance of this class, ie. create an object of this type, with the new keyword:
Ball ball = new Ball();

Then, you can access the fields from this object:
rect(ball.x, ball.y, ball.radius*2, ball.radius*2);

Notice the lowercase, crucial to distinguish the class name (usually starting with an uppercase letter) and the variable name (usually starting with a lowercase letter).

The variables you use should be in the scope of the method. Either because the variables are declared globally or because the method is part of the class where the variables are declared or because the variables are declared inside the method or because the variables are input parameters of the method. In this case you probably need the latter:

1. void changeShape(float x, float y, float radius) {

Thank you all very much, I got the information I was looking for. :)