movies

Everyone should watch the first 2 Alien movies (if they haven't go and rectify it now, I'll wait...), then, if they like them, the third. Probably force the fourth down you for completeness.

Alien: Romulus mercilessly reuses elements from all four, so it is handy to have seen the lot but required that you watch the first two (the nightmare scenario would be watching Romulus first and it spoiling the best bits of two of the greatest films ever when you get around to them).

The prequel films... you can watch them but nothing is lost (and plenty gained) if you don't. However, by this point you are 3-5 films in and it may seem silly not to. Which is how they got me.

Romulus is made for new audiences and I think only missing context is the goo/engineer lore. The next movie in this reboot series could explain that without people having to go back and watch Prometheus. If people go in blind they won't notice all the scenes and dialogue that are copied from the original.

The sci-fi/alien/space action thriller is the main selling point and if a person is already into that they may as well watch all of them. If they are already lukewarm on the concept then I wouldn't drag them through the whole series. There are better movies to watch.

The order of events is that Romulus takes place between one and two. You'll get more out of it having seen them. Don't bother with any of the modern versions--Prometheus, et al--first.

You could easily go back and watch the first two after Romulus. No need for homework.