Coolant reading too high

Coolant level in the reservoir is too high? This should not make a difference on whether the car starts or not. Certainly, to prevent boil over it should be reduced to the proper "cold" fill amount. The first place to start checking is your 12 volt engine battery. That battery may be strong enough to light lights, but not strong enough to turn a starter motor. A diagnostic test including state of charge and load capacity is needed. If your battery tests completely charged and good, then you have some other starting system concern that will require troubleshooting hands on.