If you want to ride MX track, just go, you don't need a riding buddy per se.
Well, perhaps I should qualify that some. Where I live there are two types of "tracks". The state/county OHV parks will usually include a track which doesn't get much maintenance, isn't too aggressive and is generally hard pack and when they water it it just gets slippery. Riding there is at least cheap.
The private tracks charge a lot more ($20 to $25 per rider in my area), keep them watered, the dirt is soft (which actually results in some major ruts) but the jumps are much more aggressive.
If you just start going to a private track you will meet other people and you can make new friends.
Rod