Horizon tricks?

Where can I learn these? What are some tricks?

If you mean horizontal tricks, the only way to learn is to experiment throwing sideways and constantly keeping the yoyo in motion.
Also keep in mind that not every yoyo can do horizontal tricks well. Use a V-shape yoyo with a KonKave bearing for best results.

Learn Banana Turnover, on Rethinkyoyo.com. Great intro horizontal trick.

What can I learn after banana turnover?

Here’s a simple one I made up.  It’s essentially the Matrix done horizontally.