Shooting, Moving, and Losing

I am a beginner at programming and i was told the best way to start space invaders. i say, okay. so all that i have down so far is a ship withe the following code

onClipEvent (enterFrame){

Mouse.hide();// this just hides the mouse

this._x=_root._xmouse;// this makes it follow the mouse left and right
// there usually is a this._y=root._ymouse but we dont want to go up at all. just left and right.

}

So the next step for me is to make it when i hit space, it fires a bullet. i have no actionscript skill but i can do anything in flash so if there is animation (i have no idea if there is) i can easily do it.

What little progress i have made is on the Download attachment.

Thank you.