Hi @BigOrangeLuLu,
Thanks for the inquiry, and welcome to the Roku Community!
Please be advised that a channel or app cannot set a Roku device to start automatically. Although a Roku TV may have a dedicated input (such as a Live TV or an HDMI port), YouTube TV (or any other app) cannot be set to launch automatically.
Hope you'll find this information useful. Let us know if you have any questions.
Kind regards,
The Roku Community Team
John
Roku Community Moderator