That does not look like a sunflower seedling to me. Whether it is a "weed" depends on you. If that is a plant you do not want growing where you do not want it growing it is a "weed", an unwanted plant.

kimmq is kimmsr

we bought a desert (or semi-desert) property with no landscaping so right now anything green is pretty much welcome

Nicotiana glauca. Non native and invasive in some areas.

interesting.....we're on an acre and this seems to be the only plant like this on our property or on the adjacent vacant land. I understand it will get flowers. It's a keeper as far as we're concerned. thanks