This way of saying that someone lives close by is just a shortened " A couple doors( homes) further up the road from me" It does not infer up or down, or any particular direction. It could be said " a couple of doors away from me" and it might be easier to understand in that way. I hope this does not confuse you any longer .

" just a couple of doors up from me." I sure this community does not have any high rises, but single homes. The street is on an incline so counting from past my house we go up the street passing one house, and the second one is where the Whites live.

a couple of doors up from me = a couple of houses. door = house More examples: He lives next door. (one door up from me) He lives two doors up from me. He lives three doors up from me. That is how we say it, so do learn it.