How to apply transformation to imported Assets?

Question

I am trying to make a simple program that displays 3 different imported assets at different locations in the world. They are all rendering properly, but I can't figure out how to apply transformations to them to get them placed at different points in the world, how would I go about doing this? I will paste my code below, but please be kind as I just started learning MonoGame 3d a few days ago. Any other suggestions for optimization would be welcome as well.

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
using SharpDX.Direct3D11;
using System.Collections.Generic;

namespace TestGame
{

    public class Game1 : Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;

        //Camera
        Vector3 camTarget;
        Vector3 camPosition;
        Matrix projectionMatrix;
        Matrix viewMatrix;
        Matrix worldMatrix;
        Rectangle screenRectangle;

        //Geometric info
        Model ground;
        Model cube;
        Model sphere;
        Texture texture;
        Vector3 sphereCords;
        Vector3 groundCords;
        Vector3 cubeCords;
        BasicEffect basicEffect;



        List<Model> modelList = new List<Model>();
        List<Texture> textureList = new List<Texture>();



        //Orbit
        bool orbit = false;

        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
        }

        protected override void Initialize()
        {
            base.Initialize();



            //Screen Rectangle Setup
            screenRectangle = new Rectangle(0, 0, 800, 480);


            //Setup Camera
            camTarget = new Vector3(0f, 0f, 0f);
            camPosition = new Vector3(0f, 0f, -5);
            projectionMatrix = Matrix.CreatePerspectiveFieldOfView(
                               MathHelper.ToRadians(45f), graphics.
                               GraphicsDevice.Viewport.AspectRatio,
                1f, 1000f);
            viewMatrix = Matrix.CreateLookAt(camPosition, camTarget,
                         new Vector3(0f, 1f, 0f)); // Y up
            worldMatrix = Matrix.CreateWorld(camTarget, Vector3.
                          Forward, Vector3.Up);


        }

        protected override void LoadContent()
        {
            spriteBatch = new SpriteBatch(GraphicsDevice);
            ground = Content.Load<Model>("Assets/Ground/Ground");
            modelList.Add(ground);
            cube = Content.Load<Model>("Assets/Cube/MonoCube");
            modelList.Add(cube);
            sphere = Content.Load<Model>("sphere");
            sphereCords = new Vector3(0f, -5f, 0f);
            modelList.Add(sphere);


            texture = Content.Load<Texture>("Assets/Ground/DirtGround");
            textureList.Add(texture);
            texture = Content.Load<Texture>("Assets/Cube/MonocubeTexture");
            textureList.Add(texture);


        }

        protected override void UnloadContent()
        {

        }

        protected override void Update(GameTime gameTime)
        {
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back ==
                ButtonState.Pressed || Keyboard.GetState().IsKeyDown(
                Keys.Escape))
                Exit();

            if (Keyboard.GetState().IsKeyDown(Keys.Left))
            {
                camPosition.X -= 0.1f;
                camTarget.X -= 0.1f;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.Right))
            {
                camPosition.X += 0.1f;
                camTarget.X += 0.1f;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.Up))
            {
                camPosition.Y -= 0.1f;
                camTarget.Y -= 0.1f;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.Down))
            {
                camPosition.Y += 0.1f;
                camTarget.Y += 0.1f;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.OemPlus))
            {
                camPosition.Z += 0.1f;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.OemMinus))
            {
                camPosition.Z -= 0.1f;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.Space))
            {
                orbit = !orbit;
            }

            if (orbit)
            {
                Matrix rotationMatrix = Matrix.CreateRotationY(
                                        MathHelper.ToRadians(1f));
                camPosition = Vector3.Transform(camPosition,
                              rotationMatrix);
            }
            viewMatrix = Matrix.CreateLookAt(camPosition, camTarget,
                         Vector3.Up);
            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);
            DrawModel(modelList[0], new Vector3(0, -5, 0));
            DrawModel(modelList[1], new Vector3(0, 5, 0));
            
                
            base.Draw(gameTime);
            
        }


        void DrawModel(Model model, Vector3 vector3)
        {
            foreach (ModelMesh mesh in model.Meshes)
            {
                foreach (BasicEffect effect in mesh.Effects)
                {
                    //effect.EnableDefaultLighting();
                    effect.AmbientLightColor = new Vector3(1f, 0, 0);
                    effect.View = viewMatrix;
                    effect.World = worldMatrix;
                    effect.Projection = projectionMatrix;
                }
                mesh.Draw();
            }
        }

    }
}

I have tried creating Vector3 variables for each object, but cannot seem to apply them as a transformation.