Hi there , I just swapped a manual trans into a Honda civic EK 3 which earlier was automatic . Do I need to put the gearlight on park to start the car . And does the VTEC react on park when driving the car ?

Yes you need to engage in 'P' mode before you start the engine. No the VTEC is only activated in high revs.

The VTEC (Variable Valve Timing and Lift Electronic Control) Solenoid is activated by high oil pressure, when the engine is operating at high rpm. When this happens, high oil pressure causes a pin to slide into position on each cylinder's set of intake valves. Both valves then move as a unit. This substantially increases air intake and horsepower (i.e. torque x rpm/5252).