How to have the screen/camera follow a box2d body as it moves

I am trying to learn how to use box2d (a lot of this code is unashamedly stolen from the legend Dan Shiffman) so I have created a small "game" where a ball rolls in Perlin noise terrain. The obvious problem with my code is that quite quickly the ball just rolls off the screen. I know I will have to change my terrain generation as it won't keep generating as the screen moves but for now I would like to know how to get the screen to move in the first place. I want to keep the the circles x value in the center of the screen.

I have found several similar questions where the answer was to move the world but that seems like a bad idea with box2d. I also found someone mentioning a camera? class but I am a beginner and have no idea what that is or how to use it.

Some of the main code:

void setup() {
  size(1000,800);
  smooth();
  frameRate(30);
  sw = new StopWatchTimer();
  sw.start();

  box2d = new Box2DProcessing(this);
  box2d.createWorld();

  p = new player(10,10,10);

  surface = new Surface();

  grav = -50;
  box2d.setGravity(0, grav);

}

void draw() {

  background(200);

  //text(sw.second(),100,100);

  box2d.step();
  surface.display();
  time();
  keyTyped();

  box2d.setGravity(0, grav);

  p.display();
  prePos = p.getPos();
}

Some code from the player class:

player(float x, float y, float r_) {
    r = r_;

    makeBody(x, y, r);
    body.setUserData(this);
    col = color(175);
  }


  public void makeBody(float x, float y, float r) {

    BodyDef bd = new BodyDef();

    bd.position = box2d.coordPixelsToWorld(x, y);
    bd.type = BodyType.DYNAMIC;
    body = box2d.createBody(bd);


    cs = new CircleShape();
    cs.m_radius = box2d.scalarPixelsToWorld(r);

    fd = new FixtureDef();
    fd.shape = cs;

    fd.density = 5;
    fd.friction = 1;
    fd.restitution = .3;


    body.createFixture(fd);

}

I am well aware this question is really poorly asked but I was unsure which code would be needed and i'm not a very articulate person so if any clarification or more code is needed to make this understandable don't hesitate to yell at me for it.

You could use the translate() command. You would put in draw with the coordinates of the player as parameters. I assume that p.getPos() returns a PVector. If this is the case, then draw would look like this:

void draw() {
  pushMatrix()
  translate(p.getPos().x+width/2,p.getPos().y+height/2); // <--Added Line
  background(200);

  //text(sw.second(),100,100);

  box2d.step();
  surface.display();
  popMatrix()
  time();
  keyTyped();

  box2d.setGravity(0, grav);

  p.display();
  prePos = p.getPos();
}