This question has been answered by BobRay. See the first response.

I don't think it's silly. We were all new to MODX at some point.
I'm not completely clear on what you want, but Template Variables (TVs) might be what you want. They hold resource-specific values and they can have default and/or inherited values.
Another possibility is language strings. They sound more like what you want. They can be in a lexicon file with keys and values. They can also be in the database if you add them in Lexicon Management. They can be displayed with language tags, or in code with $modx->lexicon('key');
If they're stored in one or more lexicon files, you have to add a snippet at the top of your pages to load them with $modx->lexicon->load().