Basic Game Adjustments

I'm currently developing a game in XNA its a side scrolling 2D tank game with 3 levels the objective of the game if to destroy the base at the end of the map. There are 3 different types of enemy helicopter, solider and tank. The helicopter will travel along way points which are set the other enemies will move towards the player and stop within a certain firing range to being attacking. So far the player start screen begins, once the game is started the player spawns and can move across the X axis firing at the helicopter which spawns along the top of the screen and shoots at the player. If the player gets hit they die and they have 3 lives are the player dies they spawn if they still have a life left. ( I set the lives to 3). What I need from the developer is help with this game which should be fairly easy - I need the scrolling background setup with different backgrounds per level, soldiers and tank spawning, following enemy with a certain range and then attacking. Lastly I would need you to setup the level change when the player destroys the enemy base at the end (which would also need to be created).