In the US, Hulu offers every single one of the movies, so it should be your one-stop shop. It's also where Alien: Earth will land. A subscription starts at $9.99 but there are sometimes Hulu deals.

So, what Alien: Earth is saying is Weyland-Yutani is aware of xenomorphs (among other creatures) well before the events of the films and was *this close* to getting one back to Earth.

Earth" is not the movie or even a movie, but a series full of character exposition and backstory. With eight hours to fill, the pacing can be unhurried too. "Alien: Earth" can also be claustrophobic — more often like "Alien soundstage" than "Alien: Earth" — plus any comparisons to the movies,