On 96 civic,motor turns over but cam won't,checked timing belt it is good and tuning

Then you have a broken cam shaft. Not uncommon in some civics. I have replaced a couple. Remove front cover, remove valve cover, remove belt, remove cam sprocket. remove hold downs and cam. Good time to replace water pump and belt.

The camshaft broke. The highest pressures in an engine are on the cam lobes, which resist rotational (radial) forces. Review your oil change schedule and only use full synthetic engine oil. Be sure to torque the new camshaft to spec. and in the proper sequence.