Before you start getting into meaning (and to help ease you into context), get to know some background information about the artist/creator, the stylistic movement, the time period, the country, and so on.
Your searches with these types of sources will be simple: Greece, flying buttress, jewelry, Etruria, hieroglyph, Lower Kingdom, Maya, Late Middle Ages, weaving, loom, lathe, sculpture, frame narrative...
You can start with simple searches here, but these resources really shine when you take advantage of the Advanced Search tool to get more complex. E.g. not just searching Japan or Buddhism but: Japan AND Nara period AND Buddhism -- you'll get fewer results, because there's more criteria they have to fit. In this case, you'd get articles about Buddhism in the Nara period of ancient/medieval Japan.
Why are these listed twice? Because books are just a format for info to be published. Some books will be more introductory, while others are more scholarly. Some might even do both! (The advantage of having a few hundred pages to work with.)
Psst -- what's a database?
In its most basic sense, a database is just a selection of information designed for you to search and retrieve stuff from it. Amazon is a database you're probably familiar with: it's limited (only contains things you can buy through them) and retrievable (you can search and filter your results to find what you're looking for).
The library databases contain reputable, reliable sources of information to support researchers like you! This means everything from digital encyclopedias (like Credo), ebooks, scholarly journal articles, magazine and newspaper articles, streaming videos, statistics, and more.