With regards to The Walking Dead, you indeed have not missed much.
Once the zombie threat becomes understood, there is nothing much where a story can go from there...except to rebuild civilization. And that's just a bunch of messy "just-so" stories based around the prejudices and politics of the author. Which is frequently boring.
I will say that the disparity between the walking dead TV show and comics couldn't be larger. It can be summed up that the TV show is about heroic characters with a show that focusses on Zombies.
While the Walking dead Comics have very little to do with zombies, instead it is the focus on a group of broken people who continue to lose what little humanity they have left.
The TV show squanders every emotional growth the comic gives them because they have to keep Rick as an identifiable paragon of manliness.
I don't want to go into it too much, all I can do is recommend the comic (and tell tale games) as a great character drama.
For those watching the TV show here is a big example; After the prisoner and the governor arc, the group come across a more "green" set of survivors, they are so mistrustful they don't even try to communicate with them, they just immediately butcher them in case they were a threat. Everything like this is whitewashed away for the show.