I’m posting these two together because they often get mistaken for each other. It seems they both bloom at the same time and so are easily confused. In fact, when I did a search for ragweed images, I saw photos of both types of plants.
This, as I understand it, is Goldenrod. It was growing against someone’s back fence and wasn’t easy to get to to take a picture of:
Some smaller Goldenrod:
This, I believe, is baby Goldenrod:
This, on the other hand, is Ragweed:
And teenage Ragweed:
And baby Ragweed:
For more information about the difference between goldenrod and ragweed, see: