I bought an hdmi cable and can get the video perfectly but sound only comes out the computer and not the tv. I went into playback devices and HDMI is not an option for sound. I read somewhere that Dell laptops don't support audio for hdmi cables, don't know if that's true. I bought a "y" adapter and plugged it into the tv and it still doesn't work. How do I get sound to my tv?
That depends on your laptop model and the GPU it is using. If you have an AMD GPU in your laptop you should see "AMD HDMI Output" in the sound playback settings. If not you may just be SOL. Generally if your TV is set to HDMI it's going to expect the sound to come from HDMI, not another source like RCA or stereo cables.