Anyone into philosophy/ethics/theology?

I’ve only studied technical fields, but I love trying (and typically failing) to engage with philosophical material. One of my old roommates studied philosophy, and we’d stay up late discussing it so I’d get tangential exposure and a good dialogue on ideas (I credit them with helping me “discover” actual theory). Anyway, they’ve been dead for a while now and while every day I wish it weren’t the case, so is my only connection to engaging with philosophical topics.

Anyway - I wanted to pick up more background info of ethical philosophy, and have been wading into Kant (like literally getting started with reviewing overview pages like this: https://iep.utm.edu/kantview ) and the page author’s summary stood out to me:

Kant’s ethics are organized around the notion of a “categorical imperative,” which is a universal ethical principle stating that one should always respect the humanity in others, and that one should only act in accordance with rules that could hold for everyone. Kant argued that the moral law is a truth of reason, and hence that all rational creatures are bound by the same moral law. Thus in answer to the question, “What should I do?” Kant replies that we should act rationally, in accordance with a universal moral law.

Kant also argued that his ethical theory requires belief in free will, God, and the immortality of the soul. Although we cannot have knowledge of these things, reflection on the moral law leads to a justified belief in them, which amounts to a kind rational faith. Thus in answer to the question, “What may I hope?” Kant replies that we may hope that our souls are immortal and that there really is a God who designed the world in accordance with principles of justice.

Maybe I’ll have my own understanding when I engage with Kant’s actual writing, but I find the mentioned notion of a “categorical imperative” interesting. I guess when I’ve heard disagreements framed as “philosophical differences”, I never took it literally (ironically), but it seems like differences in worldview stem from a disregard of the

universal ethical principle stating that one should always respect the humanity in others, and that one should only act in accordance with rules that could hold for everyone.

and it makes sense then that common ground cannot be found when opposing viewpoints are rooted in incompatible principles. (Assuming that all parties have principles of sorts).

Idk where I’m going with any of this post, but I don’t have anyone to engage in my philosophical dumbassery with, so you’re all the lucky recipients.

Also can one hop around between authors? Or is there a benefit to interacting with older material? I was interested in reading some Kierkegaard, but thought I should go through Kant and Hegel first… but should one go further back to idk… Plato?