How can I use custom shaders with a GUI in order to manipulate transformations of an object?

Fair warning, I am very new to coding, Processing and shaders. This is the code I have which uses ControlP5 sliders to change the rotation, scaling and translation of three objects, even though you can only do it with one object at a time. I was told to implement the same program using GLSL shaders but after reading about shaders for a couple days I still have no idea how to conceptualize that. I tried just using generic examples along with this code here, but I keep getting an error that my shader has to be of COLOR, TEXTURE and LIGHT type to render the geometry. How can the objects need three different shaders??

//See draw method to change the shape that appears when program is run.

import peasy.*;
import controlP5.*;

PeasyCam cam;
ControlP5 cp5;
PShape shape;
Accordion accordion;

float Tx, Ty, Tz, Rx, Ry, Rz, Sx, Sy, Sz; //variables for each axis that will be used for the transformations. T - translate, R - rotate, S - scale

  void keyPressed() {
    cam.setActive(false); //stops camera from moving after pressing any key
  }

  void setup() {
    size(800, 400, P3D);
    cam = new PeasyCam(this, 500);
    gui();

  }

  //sets up the sliders used to controll the transformations
  void gui() {

    cp5 = new ControlP5(this);
    cp5.setAutoDraw(false);

    Group g1 = cp5.addGroup("translations")
                .setBackgroundColor(color(0, 64))
                .setBackgroundHeight(70)
                ;

    cp5.addSlider("Tx")
       .setPosition(0, 0)
       .setSize(100, 20)
       .setRange(-200, 200)
       .setValue(0)
       .moveTo(g1);

       cp5.addSlider("Ty")
       .setPosition(0, 30)
       .setSize(100, 20)
       .setRange(-200, 200)
       .setValue(0)
       .moveTo(g1);

       cp5.addSlider("Tz")
       .setPosition(0, 60)
       .setSize(100, 20)
       .setRange(-200, 200)
       .setValue(0)
       .moveTo(g1);

    Group g2 = cp5.addGroup("rotations")
                .setBackgroundColor(color(0, 64))
                .setBackgroundHeight(70)
                ;

    cp5.addSlider("Rx")
       .setPosition(0, 0)
       .setSize(100, 20)
       .setRange(-360, 360)
       .setValue(0)
       .moveTo(g2);

       cp5.addSlider("Ry")
       .setPosition(0, 30)
       .setSize(100, 20)
       .setRange(-360, 360)
       .setValue(0)
       .moveTo(g2);

       cp5.addSlider("Rz")
       .setPosition(0, 60)
       .setSize(100, 20)
       .setRange(-360, 360)
       .setValue(0)
       .moveTo(g2);

    Group g3 = cp5.addGroup("scaling")
                .setBackgroundColor(color(0, 64))
                .setBackgroundHeight(70)
                ;

    cp5.addSlider("Sx")
       .setPosition(0, 0)
       .setSize(100, 20)
       .setRange(0, 5)
       .setValue(1)
       .moveTo(g3);

       cp5.addSlider("Sy")
       .setPosition(0, 30)
       .setSize(100, 20)
       .setRange(0, 5)
       .setValue(1)
       .moveTo(g3);

       cp5.addSlider("Sz")
       .setPosition(0, 60)
       .setSize(100, 20)
       .setRange(0, 5)
       .setValue(1)
       .moveTo(g3);

       accordion = cp5.addAccordion("acc")
                 .setPosition(40,40)
                 .setWidth(100)
                 .addItem(g1)
                 .addItem(g2)
                 .addItem(g3)
                 ;

       accordion.setCollapseMode(Accordion.MULTI);

  }


void move (float x, float y, float z) {
  translate(x, y, z);
}
void turn (float x, float y, float z) {
  rotateX(radians(x));
  rotateY(radians(y));
  rotateZ(radians(z));
}
void stretch (float x, float y, float z) {
  scale(x, y, z);
}

void draw(){
  background(0);
  lights();
  fill(156, 85, 232);
  stroke(255);

  //to display a different shape, add comments to whichever line is not commented below and remove comments from a different line
  //example: add comments to line 142 and remove comments from 143 to draw a torus

  //shape = createShape(BOX, 100,200,300); //stores box in shape
  //shape = getTorus(100,50,32,32); //stores torus in shape
  shape = loadShape("deer.obj"); //stores deer.obj in shape

  move (Tx, Ty, Tz);
  turn (Rx, Ry, Rz);
  stretch (Sx, Sy, Sz);
  shape(shape); //draws shape

  inFront();
  }

  //allows for drawing the 2D gui in front of the 3D objects
  void inFront() {
  hint(DISABLE_DEPTH_TEST);
  cam.beginHUD();
  cp5.draw();
  cam.endHUD();
  hint(ENABLE_DEPTH_TEST);
}

//creates torus shape
PShape getTorus(float outerRad, float innerRad, int numc, int numt) {

  PShape sh = createShape();
  sh.beginShape(TRIANGLE_STRIP);
  sh.noStroke();

  float x, y, z, s, t, u, v;
  float nx, ny, nz;
  float a1, a2;
  int idx = 0;
  for (int i = 0; i < numc; i++) {
    for (int j = 0; j <= numt; j++) {
      for (int k = 1; k >= 0; k--) {
         s = (i + k) % numc + 0.5;
         t = j % numt;
         u = s / numc;
         v = t / numt;
         a1 = s * TWO_PI / numc;
         a2 = t * TWO_PI / numt;

         x = (outerRad + innerRad * cos(a1)) * cos(a2);
         y = (outerRad + innerRad * cos(a1)) * sin(a2);
         z = innerRad * sin(a1);

         nx = cos(a1) * cos(a2);
         ny = cos(a1) * sin(a2);
         nz = sin(a1);
         sh.normal(nx, ny, nz);
         sh.vertex(x, y, z);

      }
    }
  }
   sh.endShape();
  return sh;
}