What is this “weed” with yellow flower?
We're checking our weed identification sources, but in the meantime, could you check a couple of characteristics for us?
Is the sap of this plant has milky-white sap? You can snap a leaf in half and see what oozes out of the main vein.
Are the ruffles on the basal leaf edges prickly or soft?
Our best educated guess is Oriental False Hawkweed (Youngia japonica) -- https://www.marylandbiodiversity.com/viewSpecies.php?species=14680. As you can see, it has been recorded from much of central Maryland.
Given its non-native status, we recommend removing it and, if you wish, replacing it with a native perennial suitable for pollinators.
The sap is milky and the ruffles are soft, but look like they are prickly. Does that confirm your ID of Youngia japonica?
It is reported to have milky sap, so that is a supporting trait, yes. Other lettuce-family plants with similar appearances can also have milky sap; some of these as well as other Aster-family relatives have prickly foliage while others are softer. We are reasonably certain that Youngia is the weed in question.