If you want access to stuff you can’t find in print, you need un-copyrighted works to use in print, or you just like to read, check out Project Gutenberg. It’s an online library of books, magazines, poems, articles, etc. that are no longer copyrighted. That includes most of the classics as well as works where the copyright wasn’t renewed (for example, “The Road Not Taken” by Robert Frost). It even has audio copies of many of them.
While easy access to the classics is nice, some of the other old books can be really interesting for research. There are herbals with recipes for medicines and teas. There are books with folk songs and sayings for different regions, others on superstitions, and more. If you have some free time, look through, and you might get some good ideas or useful details for your stories.
It’s also a great resource for genres and styles. Reading the early works in a specific genre really emphasizes how the genre has evolved. Short stories have changed dramatically, and it’s really obvious when you read any of the magazines of short stories (like Astounding Stories of Super-Science). It’s a good way to see what holds up 50 or more years later and what doesn’t.
Or I guess you could read for fun. You know… whatever works.