guins,
Please be a bit more specific with your posts.
Still nothing is not much to go on.
From the start, was the engine rotating ?
If the flywheel does not turn the engine can not generate an spark.
If the flywheel is turning too slow it will not generate any spark.
If the engine is not turning and the new solenoid is just clicking then generally that is caused by a flat battery or corrosion on one of the main power wires.
starting with a freshly charged battery try the following
Simple to check.
Run a jumper from your battery - to the engine block.
Mower starts fine = bad ground
Run a jumper from your battery + to the hot side of the solenoid
Starts fine = bad power supply wire
Do the same as above to the starter side of the solenoid
Starts fine = duff solenoid
Dosn't start properly = duff starter
Before you do any of these check the valve lash.
I get a dozen "unfixable" mowers in every season where the owners have replaced some or all of the following for a cost of around $ 400 when all the mower needed was a valve adjustment.
Starter motor , solenoid, battery, ignition switch , PTO switch, Ground lead, Power lead.