I know there’s an entire world out there of people who know exactly what they’re doing, but it’s all quite confusing.

I think it is really easy to get overwhelmed because there are people who really geek out over coffee and that level of geeking out isn't necessarily required to find something you enjoy more than what you do now. It is a bit like bread, you can use a bread machine with the recipe booklet that comes with it and get something so much tastier than store brand sandwich bread but all the folks talking about bakers percentages or high hydration sourdough techniques can make it seem like you need a degree to even think about not buying bread from the store.

If I’m typically only ever making coffee for myself, what should my brewing method be? Nespresso? Pour-over? French press?

I use a French press (which come in a variety of sizes) and I find it way less intimidating than some other options. If the idea of actually brewing the coffee is something you are worried about James Hoffmann, a name you'll see mentioned plenty around these parts, has a playlist of his techniques for different brewing methods (link) and a beginner's guide playlist (link). The first one will help you know if one seems less intimidating or works better with the equipment you have or can afford and the latter will introduce you to some basic concepts and things to consider.

And should I be looking to try everything black, or are lattes and whatnot a good way to learn what my tastes are?

If you are trying to approach it without any established preferences I'd say go for a variety. You might find the additive or no additive preference changes depending on the coffee (such as preferring light roasts black and dark roasts with milk) or the brewing method (finding straight espresso too strong but loving a nice cappuccino). You'll never know until you try.