I won't spoil it to you, so, off the top of my head I'd recommend you watch star trek tos season 01 episode 22 "space seed" then the movie "the wrath of Khan" t

I won't spoil it to you, so, off the top of my head I'd recommend you watch star trek tos season 01 episode 22 "space seed" then the movie "the wrath of Khan" then Star Trek Enterprise season 4 episode 6 "the augments" then DS9 episode 16 season 5 'dr bashir I presume ?' (chronological order, switch ST Enterprise with ds9 if you want release order). There's a kind of resume of all that in Strange new world first episode (there's also another episode regarding genetic modification but considering it didn't prevent all the other episodes from happening then I suppose it can be skipped but it shows how strong is the opinion of the federation on the subject). I don't remember they talk much about the eugenic wars in TNG so it's most likely why it's not on your radar. They are all on Netflix at the moment. If you want to watch only one episode I highly recommend the Star Enterprise one (and there's a nice tie-in with TNG ;).