As for learning to trackstand (one word), I did pretty much what you're doing. It took me a month or so unil I could hold it for 30 sec or so. After about a year, I could ride across the city without putting a foot down.

Trackstanding is cool in that the more you ride, the better it gets. There isn't really any point at which I could say "now I can trackstand". It just develops.

If you want to make it useful for the track, practice with your right foot forward.

I had a theory that the reason that you see most kids standing with their left foot forward is because of the way the roads are crowned. Turning the wheel to the left lets you use the crown to keep you in place. This was verified when I noticed that the kids in Bangkok predominantly stand right foot forward because they drive on the left here.