Ok, so as a starter, I’d recommend that someone going by the above do a kind of seven episode primer on Star Trek and what it’s about. Moral/Ethical philosophy.
TOS - Balance of Terror, is preemptive aggression ever justified?
TNG - Measure of a Man, what makes a person a person?
DS9 - In The Pale Moonlight, do the ends justify the means?
VOY - I’d go with Equinox parts I & II over Year of Hell, but also a “do the ends justify the means.”
ENT - Judgement, is justice arbitrary or universal?
Skip DISCO, plenty of issues to be examined but each one takes a whole season.
Skip LD, there’s a few issues but they’re not as well presented.