Toro ready start lawn mower dead
We need to divide the problem in half. In the case of an engine we need to decide if it's not starting because of gas or spark. Too test the engine for spark your going to need an extra set of hands or some electrical tools. If you have help you can have some one hold the spark plug wire close to the spark plug while you pull the string. If electricity is getting to the spark plug you will see a spark jump from the wire too the sparkplug. IF you see a spark we can now trouble shoot the fuel.

The easiest way to check the fuel would be to buy a can of ether, that is what the guy in the video sprayed into the engine. If it runs for a couple seconds (or even acts like its about to start) then we know the problem is with the carburetor or fuel system in general. 

If you complete these next steps please come back and +1 my answer(so I get a notification) and I will continue to assist you in trouble shooting. Regardless if it's spark on fuel the trouble shooting only get more and more complex from here. I would replace the spark plug and if that doesn't work I would look at calling Home Depot, they might even pick the lawn mover up for you. They are good people.

How to check for spark video https://www.youtube.com/watch?v=mUOmsGiirTU