Ignore the 1 star reviews they be summed up by "I don't like the casting choices" and "it's not EXACTLY like the book".
Unlike the movies, this show is much truer to the book. As for the casting choices and slight variations, this is Rick's story and if he approved these changes then I don't see a problem with it.
Overall, we have been dreaming of a more accurate representation in film of this great story for years. We finally have one. It's a shame people hate it just because a character looks different or there are some changes.