Got it -- thanks! Quick followup. I'm aware that Halo has a rather sprawling expanded universe. Novels, comics, whatevs. I've heard the games are best enjoyed with supplemental material being taken into account. Do you have any recommendations therein by chance?
As someone who's read most of the novels: don't worry about 'em. If you find you enjoy the universe enough to delve deeper into the background lore, there's some excellent stuff out there like Greg Bear's Forerunner trilogy. But by no means are they mandatory
Halo Mythos is a good one if you want to learn more, as well. The Eric Nylund books are great too, though Fall of Reach was partially retconned by the game and First Strike has pretty much been forgotten.
If you find yourself lost going into Halo 4, check out the Kilo 5 trilogy (or rather read a summary online). Karen Traviss' work is rather divisive, but a lot of stuff she introduced has carried over into the rest of the universe.
If you like the ODST characters, you can check out New Blood and Bad Blood. The latter takes place post-Halo 5 however.
Also, stick to the shooter campaigns for now. If you find you really want more Halo, give Halo Wars 1 and 2 a whirl after you're done. Halo Wars 2 plays a role in the buildup to Infinite, but other than that the stories aren't really important.
As for Halo 4 Spartan Ops: just check the cutscenes online or read a summary after playing Halo 4. In no way is it worth playing through in 2020, and it was received so badly that its important plot points only got resolved in a comic.