What models are your Yamaha receiver and LG4k TV?
How many speakers? Any other devices; e.g., DVD player involved?
Based on the specifications and images that I found by googling you may have a variety of options.
Start with the applicable User Guides/Manuals for your devices.
And these two links may be helpful:
http
/www.diyaudioandvideo.com/TV/WiringDiagram/
http
/www.ceaconnectionsguide.com/
Just sketch out your own diagram and start fitting things together.