What zone are you in?

7b

Sorry ... I’m in 3b so not sure what the possibilities would be for you. If you were in my zone, I’d hazard a guess at Alpine Currant, but no idea if that would apply to you. You could cut off a piece, place it in a plastic bag and take it into a local nursery. I’m sure someone could help you. (Don’t bother with the big box stores ... it’s rare to find someone who really knows their gardening stuff there.)

It could be a Cucurbit of some sort. Can you show the base of the plant and the stems. It is difficult to see if the leaves are opposite or alternate.

That is Anemone x hybrida, a late summer/fall blooming Windflower. Not a weed, but it is a very rambunctious spreader.

Yes, it’s Japanese anemone. Valuable for late summer blooms. But it does spread. However, not difficult to keep within bounds.