So my brother loves the Gundam Wing series and he really wants me to watch with him the movie “Mobile Suit Gundam: Hathaway”.
However, I have never really watched the Gundam series as - I was never really into Mecha besides a few animes.
Thus my question is: Can I watch the Hathaway movie without knowing anything about the anime series?
Can you watch it with no context, mostly yea, but you miss out on some of the motives. Mainly Hathaway, on why they are on this mission
I guess you cannot watch this one without knowledge about Gundam. You need to know at least about civil war and the role of Hathway-senior in it... Otherwise you can enjoy mecha battles scenes but you will lose a plot.
A lot of the stuff in the Universal Century (UC) timeline of Gundam will make a lot more sense if you've seen the first three shows and movie:
Mobile Suit Gundam (some people will recommend the compilation movies - the show is much better imo)
Mobile Suit Zeta Gundam
Mobile Suit Gundam ZZ (some people recommend skipping this one - they're wrong)
Mobile Suit Gundam: Char's Counterattack
The Hathaway movies serve as a direct sequel to Char's Counterattack (they're based on a novel written by the series original creator), and CCA builds on events in the three TV anime preceding it. I know it's hard to recommend ~150 episodes of a cartoon and a different movie, but you'll probably enjoy the Hathaway movie more.
If you do the homework or not, it's a pretty cool movie with some good visual set pieces. Enjoy!