The timing belt service interval is ~ 100K, so if it hasn't been done yet I would put it on your list.
Is the engine still flooded? Are the plug tips wet with fuel? This can keep them from firing.
Remove the plugs, unplug the coil connector and crank the engine over to dry the cylinders. Remember that fuel vapors are flammable, keep any spark away.
You may want to use only the recommended spark plug type as others can cause issues. Wrong parts aren't an upgrade. The correct heat range was chosen carefully.
I show Champion RE16MC or NGK LZYR4A-11. Check your owners manual or the underhood emissions label for the correct spark plug type.