Is this an area that you are growing flowers or vegetables in? It's difficult without more info (like bloom and when) to be certain but the first photo could be a weed called Eclipta, which would have had tiny whitish ball flowers in August to September ripening to a small, green, button-like fruit.
Your second photo looks like an ornamental. Do you think you planted it? How large is it? When did it come up?
The third photo appears to be a plant in the parsley or carrot family.
Well.... the short answer is, I don't know. These pix are from the garden at Georgetown Lutheran Church in DC. The former gardener left after planting one of everything, and for a few years the garden has been untended. I have taken on the project. Rocks in my head.
Not sure what to pull up as weeds. I think #1 is probably a weed, judging from where it is. The second I will leave for next year and maybe send you pix when things bloom. The third seems very odd for a church garden, but it is doing no harm!
Yes, #1 looks like a weed. If you want to send us photos of the other two plants when they are in bloom, we would be happy to take a look and try to identify them for you.