I just replaced the starter in my Craftsman lawn tractor. I put in a new battery at the same time. The tractor will not start it doesn't even turn over?

Check to see if you can turn the thing over by hand

Check solenoid or safety system.

How do I check safety system on 20 hp jd lawn tractor? I see the one under the seat,where is the cutter deck and shift lever switch?
Thanks
Ed