***"now it won't start!"***
Not much of a description there.
I will guess that when you turn the key now, you get no sound at all.
If that is what you mean, first check the position of the PTO switch. if it is ON, the starter is inhibited from engaging.
If the PTO switch is OFF, check for a blown fuse.
No blown fuse? Try boost starting from another vehicle with jumper cables.
If that is fruitless, check and clean ALL battery cables on the mower, that means ALL cable ends on both the negative and positive cables, and the cable between solenoid and starter too.
If none of these apply to your case, try posting a bit more descriptive version of exactly what is, or is not happening when you turn the key to start.

no it turns over but wont start sounds like it want to start but just wont checked all cable pto not engaged brake depressed choke on key on fully charged battery ?????

2 things to check right off.
Check for spark at the plug. You can do this by removing the spark plug, connecting the plug back to the spark cable, then lay the plug on a metal part of the engine where you can see the spark end of the plug. Watch for spark while someone sits in the seat and cranks the engine.
If you do not have spark, post back stating that.
If you have spark, put the plug back in and go to the next step.
Remove the air cleaner and spray a burst of spray carb cleaner into the carb, or drop a couple of teaspoons of gasoline into the carb and immediately try to start the engine. If the engine runs for a second or 2, there is a problem with the fuel system not delivering fuel to the engine. DO NOT use "ether starting fluid" in a small, air cooled engine.
Do this and post back.

we have spark and fuel going to carb new plug and new fuel filter new fuel line oil change and filter also

Fuel getting to the carb does not equal fuel making its way through the carb and into the engine. That is why the part about dribbling a couple spoons of gas, or a shot of carb cleaner into the throat of the carb is significant.
What happened when you did that?