Oh boy! I've lots of suggestions for you!
It WOULD help to know where you are located though.
For me in NJ, starting early in spring, there's Ground Ivy, which is a non-native weed that nobody likes but it's about the only ground flowers around and bees love them. Then -- sticking more to native plants, we have violets, Winterberry Holly flowers and Inkberry Holly flowers, Tiarella, Viburnums, native azaleas, and Kalmias, Blueberries and Cranberries, Virginia Sweetspire, Iris versicolor, Marsh Marigold. And let's not forget Swamp Red Maple and Swamp Magnolia or Golden Alexanders.
Into summer, there's Summer Sweet which is usually COVERED with bees, wild day lilies, Monarda (or any other mint for that matter -- Peppermint, Spearmint, Applemint...), Spicebush and Buttonbush, Red and Blue Lobelias, Swamp Milkweed....
Whew, is that enough yet?
I'll think about more summer through fall flowers and post later.