Looks like Poison Ivy and some other weed

Possibly, or Virginia creeper (Parthenocissus.)

Yes, one or the other. Sometimes Virginia creeper pops up with 3 leaves on the first true leaf and then has 5 on the next set.

Cotyledons match Vitaceae.

Yes I agree that Grape seedlings start out that way too, until you get to the true leaf.

Right, I was confirming Parthenocissus rather than Poison Ivy.

Oh I see what you mean. I actually had not realized that Parthenocissus was in the Vitaceae family. Learn something new every day! :)