In reply to iiswoz:
Hiya, ignore Phillip. I think he may be making a joke.
Glad you had a good first climbing experience and you're curious about how leading works.
The lead climber starts at the bottom of the climb and ties onto the rope.
The leader starts climbing and as they work up the climb they place protection into the rock (various ways). If the leader falls they will fall to beneath (and potentially further) their last piece of protection
The second belays the leader from the bottom by paying out slack as the leader climbs and holding any potential fall.
Once the leader gets to the top of the pitch/climb they place multiple pieces of protection and link them together in a similar method to how your top ropes were linked.
The leader pulls up the spare rope betweent them and the second, places the second on belay and then belays the second from the top of the climb/pitch.