What happens next?

How to tail whip
Practice your jumps and airing out.
To do a bmx tail-whip, you'll need some serious air. It's hard (though not impossible) to tail-whip from the ground, so practice on a quarter-pipe or other jump that you can get up off the ground high enough to whip the bike around safely and have a chance of landing it.
Practice getting big air and turning around clockwise to aim forward as you land. One good exercise when you're trying to learn is to kick off your far leg.