How do I turn tv power on and off with apple tv remote?

First, your TV has to be compatible with HDMI-CEC which allows compatible devices to be controlled by other devices over the HDMI cable. Most audio/visual equipment manufactured in the last 10 years is compatible with the standard.

Be aware, in my opinion, this is a very poorly implemented standard so your success with it may vary. This wikipedia article covers the names used by various manufacturers to describe HDMI-CEC, https://en.wikipedia.org/wiki/Consumer_Electronics_Control

Once you have enable HDMI-CEC on both your TV and on the Apple TV waking up the Apple TV will cause your TV to turn on. Causing your Apple TV to go to sleep, by holding down the TV button on the remote and selecting sleep, will cause the TV to turn off.

If you have other A/V equipment as part of your Home Theatre mix like an A/V receiver or Blu-ray player, especially if they are from different manufacturers, you may find HDMI-CEC does not work as intended. Again, YMMV.

Good luck.

You actually put it to sleep you can’t completely turn it off.

To do that just long press the little screen button on your remote and select Yes.

I hope I answered your question.

If you post the model number of your TV I may be able to find a PDF of the manual and point you in the right direction.

I started with CEC turned on, but had to turn it off since I use my TV with a Sat Box and on its own. The Apple TV would turn the TV off and not let me use it otherwise. It was like playing ping pong to keep it on. Now that CEC is off I can use the TV with other components without issue.

So you're trying to control your TV set and not the Apple TV right?

You've just experienced what I mean by, "very poorly implemented standard."

I don't know why the A/V component manufacturers even bothered. They never get any of this inter-operational stuff correct.