How to fly a parabolic arc?
Get lots of airspeed,pitch up within ac flight envelope limits and as you approach stall speed for your configuration, push forward so that 0 G is shown on the g meter, and keep it there.
As you come over the top pull out again within it's so you neo not exceed Vne,Vmo or Mmo or g limit's for your planes . A parabola for a few minutes or second depending on the plane.