The first photo shows a mulberry tree seedling. It's probably best to remove it because it will grow rapidly and compete with plants that are more beneficial to butterflies and pollinators.
In the middle photo is a wildflower known as bidens. There are several species. They do attract pollinators but they also bear seeds called beggarticks or stick-tights. The seeds can be a nuisance because they cling tenaciously to clothing.
The plant in the photo to the right is three-seeded mercury (Acalypha rhomboidea).
It's a native plant but is generally considered a weed and isn't known to attract butterflies or pollinators.