I got a new cable box and plugged everything up with HDMI cable and my vizio will not give me a picture, it says no signal. This same thing happened the last time I had to change my cable box and I cannot remember how to fix it

You should have a cable line connected to the cable box, then the HDMI from the cable box to the TV.

Note which HDMI input you used (should be labeled with a number).

Then using your TV remote, either repeatedly press the "HDMI" button until it is on the matching input, or look for a "Source" or "Input" button.