If you want to spend your free time watching this movie just to prepare for the second part coming out next year, go ahead. But if you're expecting a scary, intense film, then you probably won't want to waste your time and money on this one. Remember when the trailers were praised for not revealing too much, that's because there's nothing much happening in the movie and it's like it's only the first one out of 12 episodes of a TV series.
The first scene in the movie was actually the most terrifying scene in the entire film, but it's way too rushed unlike the first scene in 28 Weeks Later which was probably the most intense opening scene in a zombie movie.
Despite all that, I still want to watch the sequel (because I really like this zombie concept and I want to see Cillian Murphy back) but I will only do it after reading the audiences' reviews, not the critics' because this film got 93% score on Rotten Tomatoes which is bs.