Volunteers in flower beds
Good Afternoon! I've consulted with our Horticulture Specialist and we think it is Prunus serotina, Black Cherry, which has seeded into your garden bed. To learn more: https://plants.ces.ncsu.edu/plants/prunus-serotina/
Morning! This looks like a mulberry seedling. Removal is also suggested. To learn more: https://www.extension.purdue.edu/extmedia/fnr/fnr_237.pdf
You are very welcome! Enjoy the fall season!