Hello. After some time i have noticed that the rendering method i use is not to handy nor easy to understand

Instead of moving the entire world to the camera i would like the camera to move around instead.

This is my first game and its very early in development(you can only steer the snake now :D).

Here are functions i use to render the world:

  public void render() {
        this.clearScreen();
        this.renderGrid();
        this.rederSnake();
    }
    private void clearScreen(){
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glClearColor(0f, 0f, 0f, 0f);
        glLoadIdentity();
    }
    private void renderGrid(){
        //set up the camera
        glTranslatef(0, 0, -35);
        glRotatef(35, 1f, 0f, 0f);
        //rotate the snake and the camera
        glRotated(snakeRotationAngle, 0, 1f, 0);
        glTranslatef(-(level.getSnake().getPosX() * squareSize + (squareSize/2)), 0, (level.getSnake().getPosZ() * squareSize - (squareSize/2)));
        //render the grid
        glColor3f(0.5f, 0f, 0.5f);
        glBegin(GL11.GL_QUADS);
            for(int j = 0; j<level.getGrid().getzSize();j++){
                for(int i = 0; i<level.getGrid().getxSize();i++){
                    glVertex3f(i * squareSize + squareBorder,0,-(j+1) * squareSize + squareBorder);
                    glVertex3f(i * squareSize + squareBorder,0,-j * squareSize - squareBorder);
                    glVertex3f((i+1) * squareSize - squareBorder,0,-j * squareSize - squareBorder);
                    glVertex3f((i+1) * squareSize - squareBorder,0,-(j+1) * squareSize + squareBorder);
                }
            }
        glEnd();
    }
    private void rederSnake(){
        glLoadIdentity();
        glTranslatef(-squareSize/2, -squareSize/2, -20);
        glRotatef(35, 1, 0, 0);
        this.rotation += 6;
        if (rotation % 360 == 0)
            rotation = rotation %360;
        glTranslatef(squareSize/2, 0, -1.5f);
        glRotatef(rotation, 0f, 0f, 1f);
        glTranslatef(0f, 0f, -1.5f);
 
 
        glBegin(GL11.GL_TRIANGLES);
            GL11.glColor3f(0f,0.13333333f,0.4f);//royal blue 5
            GL11.glVertex3f(headXCoords[0], headYCoords[0], -0.5f);
            GL11.glVertex3f(headXCoords[1], headYCoords[1], -0.5f);
            GL11.glVertex3f(0, 0, -3.5f);
 
 
            GL11.glColor3f(0.152941f,0.250980f,0.5450980f);//royal blue 4
            GL11.glVertex3f(headXCoords[1], headYCoords[1], -0.5f);
            GL11.glVertex3f(headXCoords[2], headYCoords[2], -0.5f);
            GL11.glVertex3f(0, 0, -3.5f);
 
 
            GL11.glColor3f(0.22745098f,0.3725490196f,0.80392156863f);//royal blue 3
            GL11.glVertex3f(headXCoords[2], headYCoords[2], -0.5f);
            GL11.glVertex3f(headXCoords[3], headYCoords[3], -0.5f);
            GL11.glVertex3f(0, 0, -3.5f);
 
 
            GL11.glColor3f(0.282352941f,0.462745098f,1f);//royal blue 1
            GL11.glVertex3f(headXCoords[3], headYCoords[3], -0.5f);
            GL11.glVertex3f(headXCoords[4], headYCoords[4], -0.5f);
            GL11.glVertex3f(0, 0, -3.5f);    
 
 
            GL11.glColor3f(0.25490196f,0.4117647f,1f);//royal blue
            GL11.glVertex3f(headXCoords[4], headYCoords[4], -0.5f);
            GL11.glVertex3f(headXCoords[5], headYCoords[5], -0.5f);
            GL11.glVertex3f(0, 0, -3.5f);
 
 
            GL11.glColor3f(0,0,1f);// blue
            GL11.glVertex3f(headXCoords[5], headYCoords[5], -0.5f);
            GL11.glVertex3f(headXCoords[0], headYCoords[0], -0.5f);
            GL11.glVertex3f(0, 0, -3.5f);
        GL11.glEnd();
    }

I am aware that there is better way of sending the vertices, but i feel like doing it this way for now.

So i have modified this code and i deleted all the rotations and translation from around the functions and i added a new one that does the camera steering:

//everything is drawn on x and z axes, so y is the height.
private void setUpCamera(){
   glRotatef(45, 1, 0, 0);
   //rotation 45 degrees around the x axis
   glRotatef(snakeRotationAngle, 0, 1, 0);
   //rotation n degrees around the y axis(player steering)
   glTranslatef(-squareSize * this.level.getSnake().getPosX() - squareSize/2 + squareBorde   r, -25, squareSize * this.level.getSnake().getPosZ() - 25);
   //I translate the snake to the center of a square and to its position.
} 

My question is: if im rotating the camera 45 degrees, and afterwards i move away from 0,0,0 by posX and posZ, the camera should be in the air looking at the grid at 45 degrees angle on height (simplified posZ = 0) posX * tan(45).

Why does this code work? And why do i have to translate the camera 25 up to see something(i got this after some trial and error)?

Or maybe somebody has a better way of doing this?