Hello and welcome to Just Amswer,
Take the air filter off of it and put a little bit of gas into the intake and then try to start it. Try that and let me know what it does.
I am reluctant to try this because when I turn the key I get absolutely nothing. Its not like it is trying to catch but doesn't. I get NOTHING!! Why are the wheels locked even when I shift to neutral? I should be able to roll my mower when in neutral.
Take the spark plug out of it and then try to crank it. See if the engine will even turn over. If it will still not do anything then we need to check the electrical system. I would start by checking the main fuse. It will be close to the solenoid. It will look like a normal blade style fuse. As for the unit not moving, the parking brake may be stuck or the belt may be jammed.
Checked the fuse it is good. Removed spark plug and still nothing. Could the wheels be locked due to a safety feature and thus preventing startup? I can't help but think the two are related. I have never had a problem starting this mower and I just started it about three weeks ago after we experienced low temperatures. And it started up just fine.