"They are going home."
Translation:One idą do domu.
So it's 'domu' because inanimate masculine nouns take an '-u' ending in the genitive?
Not every noun does that: ołowek - ołówka (pencil), komputer-komputera (computer). But in many cases that is true.
So are "One" and "Oni" interchangeable? Or does one signify a group of men and one a group of women?
You're close. "Oni" means, that in the group there is at least one male human being. "One", for everything else. It shows that there is no male human being in the group.
Theoretically "one" could denote not only women/girls, but also boxes, cats or trees. In fact, it is really rarely used to denote something else than people (you just specify the subject, usually), so it's safe assume that's a group of women-only.
I thought it was 'domu' because it is in locative as it refers to a location?
Usually it would be, but not with "do". "do" needs Genitive. Which is the same in this example, but then you'd have "Idę do szkoły" (Genitive) and "Jestem w szkole" (Locative).
What's the difference between chodz,a and id,a (can't do the polish characters). Well, really the two verbs in general because I don't know infinitives yet. Does one mean walk and the other go? They don't seem to be straight forward based on the sentences I have seen this far.
"chodzą" (infinitive: chodzić) means: to go, to walk (generally, habitually) and sometimes also "to be going" (right now, but without any direction and purpose)
"idą" (infinitive: iść) means: to be going, to be walking (right now, with some direction)
So, I understand that with longer sentences where there is more context, it could be easily chosen which word to use, but with short little sentences like "I go" or "I walk", is it fair to say that either verb could work?
Both "I go" and "I walk" should be "(Ja) chodzę", as Present Simple implies that it's happening generally, habitually.
"I am going" and "I am walking" are obviously right now, so "(Ja) idę".
The only more difficult situation is when "I am walking" is basically the whole sentence (not "I am walking to school"), then it can be "Chodzę". It's like "Oh, I am just walking around..."
Well, "chata" is either a totally colloquial word for "house"... or it's literally a "shack".