How do I sart a 960 correspondence game?

See the green menu bar above?

Play/Online Chess.

You'll see an "open seeks" link in the frame on your right. Check it out for any 960 games you might be interested in.

If there is none,

click on "Start new game" link on the right, in the same online chess page.

Then choose "with... game options I select."

And below that, choose, "chess 960".

Specify further if you wish, with rating range etc, and wait for an opponent to accept your seek.

Or:

Again the menu bar. Play/Tournaments.

And click on "view all upcoming tournaments."

And find a 960 chess tournament.

Have fun.

Cheers.I have been playing around with this for a while without  success.

I thought maybe I had to be a premium member. i will follow your instructions.