Which plants are these... meaning which kind of soil here, in central France ?

Hello everyone!
We just started looking after a patch of earth next to Vichy, in central France, we are inexperienced gardeners... and the first thing we'd like to understand is how the soil is below our main plot!
So I took pictures of the plants which had grown since the last ploughing of the land (which will hopefully not happen again on our watch) (about 4 months ago), and I am asking for some help: if you recognise these, could you tell me which they are and, even better, what they mean regarding the soil below?
Here are the pictures, and thanks a lot!
Damien

Probably not much help but hopefully someone else will get the others:

1 ) Maple leafed goosefoot?
2 ) Red fescue?
4 ) Certainly a nightshade probably black nightshade- Solanum nigrum
7 ) Milkweed- Euphorbia
8 ) Some sort of Thistle

plant #10 looks like an amaranth. leaves are spinach , seeds in the heads are edible seed , tiny and crispy and hard to winnow. there are many varieties of amaranth . mostly edible the common wild one that grows around here is very good spinach , very mild.
the one i grew this year has large dark red flowers /seed heads . now drying in bundles in open top plastic bags to catch the seed.

I think 5 might be Annual mercury Mercurialis annua

Thanks a lot for your replies, all of them seeming very right and so being very helpful!

Here are two last ones if you would have them:

The first is a geranium but I do not know which one, I'm afraid my books all deal with northern europe!
The second could be Fallopia convolvulus (black-bindweed or wild buckwheat)

Plant 3 is phacelia, a great bee plant and nitrogen fixer. Plant 11 is malvacea family, medicinal somewhat. But if you want to know what kind of earth you have ask neighbours or look for indicator species. Kinds of plants that tell you what kind of éarth you're on. There are certain species that need alkaline soil and others need acidity. Google bio indicateur or indicatrices.