Once you have plugged your laptop to your TV via HDMI, make sure you know which port number you plugged it into, the PC input
could effectively do the same thing however. Then, look at your laptop's keyboard, look at the F keys at the top of the keyboard, if you see a button that looks like one of these, then it's the monitor button. (Yours may not be F5, for example, mine is F8, just look at the icon on the key.)
Hold down the Function key, (Fn) and press the monitor button, continue tapping the button until you get it to display on either just the TV, or the TV and the laptop screen together. If this doesn't work, try pressing the...