I was in the same spot a few months ago — constantly confused, checking random sources, and still ending up with half-baked decisions about what to buy. What helped me finally understand everything was stumbling across
https://dmarket.com/cs2-wiki/ right in the middle of my search, because it laid out collections in one place without making things overly complicated. I started comparing items, learning which drops are rare, which collections usually rise in value, and which ones are just fun to buy for aesthetics. Once I had all that info clearly laid out, choosing skins stopped feeling like guesswork and finally started feeling like something I could approach with confidence.