I hooked up an HDMI cable to my TV and only the video transmits to the TV. Audio stays on the Mac. Solution to get audio on the TV?

Assuming your Mac is relatively new, visit System Preferences > Sound > Output and select the entry that matches your TV. If there is no entry for your TV, your Mac may be too old to have audio out through HDMI, in which case you may need to run a separate audio cable.