What plants are these?
The seedling may be a Sunflower, but it is too nondescript at present to identify from the photo. The Sunflower family is large, and many similar species grow in our area, including those that have escaped being eaten as bird seed or from a neighbor's decorative sunflower stalks. If you wish to keep it and let it mature, we can try to ID it when it blooms.
The other plant resembles Blazing-Star (Liatris spicata), but this will be more evident when it comes into bloom. Flowering time is soon for Liatris, but if this plant is too young, it may not bloom this year. (If it does but it's not a match, please send more photos.) They are commonly used in native plant and pollinator gardens in Maryland. You can compare the flowers to these pictures: https://www.illinoiswildflowers.info/wetland/plants/msh_blazingstar.htm
Thank you, Miri!