Not entirely sure about how to do a pong game myself (my programming experience was on the Amstrad and I just got myself DB), but. . .
Have some sort of screen border. You need two seperate sprites, one for a ball, and one for a bat, which can be duplicated. Two player mode should be fairly easy, you just need a routine to simultate the angles that the ball is going off. Against the computer however would be a problem. That bugged me when I thought I'd try it anyway. I have seen in www.blitzcoder.com a simpe how-to on pong. Look for 'Writing a simple game in Blitz Basic'.