## There is no single complete and official (by which I take you to mean, Vatican-sponsored) interpretation of the whole Bible.
A handful of verses in James 5 or Matthew 16 or elsewhere have been given an “official” interpretation by General Councils or Popes, but this in no way hinders Catholic scholars from commenting on them - they merely have to avoid denying the interpretations in question.
The way to get at the sense of a passage, is to get a decent commentary, by someone qualified to write it - the Magisterium does not, and cannot, replace an encounter with the text, or with the work of thinking. And sometimes, even the very learned differ. This is part of life - it’s not cancelled by being Catholic, or by the fact that one is interpreting the Bible. There are uncertainties, many of them, for very good reasons, ranging from defective or uncertain text to obscurities of expression to grammatical ambiguities (for example): and there is no easy way to avoid this uncertainty. This is largely because the Bible is not a recent book, but a very old one, and there are many gaps in our knowledge of the “Biblical world”.
Some interpretations are better based than others - some are based on better acquaintance with the meaning of the text, & with its background, than others. The better an interpreter knows what he (or she) is taking about, the more trustworthy, generally speaking. So not all interpretations are equally valid.
I’m sorry things can’t be simplified as much as might be wished. The important thing is not to lose heart - the Bible is worth all the time we spend on it, and richly repays all the attention it gets. ##