The first one looks to me like crab grass.

Becky: I think I see what the confusion is. The OP said he "just" had seed put down, and I had it in my head that this seed was still germinating, and in any case certainly is not long enough to mow. I reread his post and see that he said "in the last month" these weeds have been growing, which suggests the new grass is older than I thought. My bad. So given the grass isn't quite so new, I'd just pull the weeds out. I could get the ones in the photo in 10 minutes. I do hope the OP updates us on what happens. A little more on type of seed, etc. would be nice, too.

Yes! That has to be it. Thank you so much!

No.1 is not clematis (nether is the last one).....that is very likely poison ivy. No.2 is Virginia creeper, Parthenocissus quinqefolia, and people who have a sensitivity can develop a strong reaction to this plant as well....contact dermatitis.....just not to same the degree as poison ivy produces. So it IS - or certainly can be - a problem! btw, if you want fast and accurate plant or weed ID's, post your question in the Name That Plant forum. That is it's whole purpose!! One of the most active forums on this website :-)