The skydiver leaves the plane and accelerates downwards because of gravity. There is very little air resistance acting downwards. The skydiver accelerates towards the ground.
The skydiver gains speed, air resistance increases but their weight stays the same. The resultant force acting downwards gradually decreases.
The skydiver's weight and air resistance force is balanced so there is no resultant force and the skydiver reaches terminal velocity. The skydiver cannot increase speed any more and the resultant force is zero.
The skydiver deploys the parachute, the air resistance increases. the skydiver slows down very quickly.
The skydiver continues to slow down and eventually the resistance force and weight balance out again so the skydiver has reached a new terminal velocity. The skydiver cannot increase speed again.
the skydiver reaches the ground and the resultant force becomes zero.