Without model numbers for both I can't be specific.
1. If both the TV and soundbar has ARC then you would connect the HDMI out of the soundbar to the HDMI-ARC input on the TV. Turn on ARC in the TV audio menu and select the ARC input on the soundbar.
2. Your TV should have an audio output (usually optical). That would be the most common way to connect the TV for audio to the soundbar,
You might need an adapter (change digital to analog or change coax digital to optical or vice versa).