Hi @Peetva.
Thanks for reaching out and congratulations on having a new Sonos Arc.
It is suggested to keep the included HDMI cable and optical audio adapter ready nearby, you have to use the associated cables with the Arc.
The Sonos app will guide you on which cables and ports to use when connecting your Arc to your TV.
This article will help you get started with setting up your Sonos Arc.
I hope the above advice helps, and if you have any other questions or run into any issues, don’t hesitate to reach out.
You may refer to this link for further assistance:
https://nl.community.sonos.com/