What happened to death note after the 5th episode?

I couldnt see this show after the episode where Light meets the girl
with the other death note. Can anyone tell me what happens afterward
in a nutshell?

I see the 30th episode, and theres all these people that I don't know!
Who the 5uck are these people?

What happened to Light's family? Where are they? Where's L?

PLEASE HELP