If you really want to make your own music, you should probably learn to play an instrument. If you have a general feel for the beat but aren’t too inclined to dealing with pitch, then percussion may be your forte. Buying the instrument is the next hassle, as you don’t necessarily want to drop a bunch of money on something you don’t know how to play yet.
Since you’ll be piecing together your musical knowledge anyhow, why not piece together your instrument while you’re at it? The Bleep Drum Kit will let you create your own beats, as well as the machine you would make them on. It gives you four sounds initially, but you will be able to program in more if you desire. There is tap tempo, reverse mode, and four selectable sequences. This is available for $60, and you can check out the video below for a general idea of how it would work.