I am trying to build a Mario style game just for learning. i am looking for help on how to add the background and have my player sprite in the center of screen as he moves along the map… also how would i add collision detection to area’s for sprite to jump onto??
hopefully someone can point me the right way 
So you’re pretty much looking for directions on how to create a 2D/Side-scrolling Platformer (“Mario-style game”) Well… I think there’s no real rulebook for making such a game (or any particular type of game for that matter), so I’ll just speak from my own experience.
So far, I’ve been developing a similar game as my learning project for the past few weeks and how I did it was:
(1) I used libgdx as the development framework. Now, this is not your only choice. There’s also LWJGL, for example. Other resources are in the Java Gaming Resources link.
(2) To add the background, you could do something like this upon screen creation:
/* initialize and load resources needed to draw to the screen */
batch = new SpriteBatch();
bg = new Texture(Gdx.files.internal("data/bgtile.png"));
bg.setFilter(TextureFilter.Linear, TextureFilter.Linear);
bg.setWrap(TextureWrap.Repeat, TextureWrap.Repeat);
bgSprite = new Sprite(bg,(int)this.w,(int)h);
…and then every time you render the screen, render the background first:
batch.begin();
batch.draw(bgSprite,0,0);
(3) To keep the player sprite in the center of the screen, you can keep track of your players previous position and your player’s new position… then, if the new position crosses the center of of your screen, adjust the rendering of your objects as necessary.
(4) For collision detection, it’s a bit easy if you’d use Box2D (this is included in libgdx) in your game. If so, you could do it using collision listeners. You can add a collision listener to your world like so:
private void createCollisionListener() {
ContactListener cl = new ContactListener() {
@Override
public void beginContact(Contact contact) {
Fixture fixtureA = contact.getFixtureA();
Fixture fixtureB = contact.getFixtureB();
}
@Override
public void endContact(Contact contact) {
Fixture fixtureA = contact.getFixtureA();
Fixture fixtureB = contact.getFixtureB();
}
@Override
public void preSolve(Contact contact, Manifold oldManifold) {
}
@Override
public void postSolve(Contact contact, ContactImpulse impulse) {
}
};
…and you just put in logic in beginContact and in endContact as necessary
For general knowledge on how to implement 2D/Side-scrolling Platformers though, this article is a very good read: