This is great advice. If you can afford it, purchasing the best-regarded hard copy field guide for some area of interest (e.g. wildflowers in California, mushrooms of Russia) can be really helpful for getting your feet under you in a larger group.
One other way that you can start small but make a huge impact is noticing species that people struggle to narrow down, but ARE identifiable from a half-decent photo. For example, I didn’t know how to tell the difference between any of the big black butterflies in my region (Spicebush Swallowtail, Pipevine Swallowtail, the black form of Eastern Tiger Swallowtail, and Red-Spotted Admiral). So I’d upload without a species-level ID, and I learned to tell the difference between these butterflies both just by practice/feedback from experienced IDers, and by perusing simple, non-technical comparison guides like this one. Now whenever I see a big black butterfly pop up unidentified in my region, I feel confident slapping an ID on that bad boy.