Here are some of the resources I've used to learn about the natural world, particularly botany:

Used book stores tend to have a treasure trove of field guides and nature books. Stock up for cheap! For wildflowers, start with a Peterson Field Guide to Wildflowers of Northeastern and North-Central North America.

Native Plants of New England Facebook group is a great place to start for plants. It makes it easy to get familiar with what's blooming now. Most posts are of things members have found recently, so you're seeing and learning to recognize plants you might see on your own next walk.

GoBotany is a simple online key that helps you identify New England plants based on simple characteristics like leaf shape, flower color, and symmetry.

iNaturalist "helps you identify the plants and animals around you. Get connected with a community of over a million scientists and naturalists who can help you learn more about nature! What’s more, by recording and sharing your observations, you’ll create research quality data for scientists working to better understand and protect nature."

The Native Plant Trust in Framingham MA offers really great classes and field studies online and in person.