The first and 4th are weeds.
Number one is a Spurge - euonymus,
2 is a random collection of weeds.
4 is a dreaded buttercup.
I dont know about number 3.
I agree with lyn, number 3 looks like a cross between a dicentra and aqualigia!!
The first one is a weed it's a euphorbia type weed they do seed nicely in drifts lol my lo also enjoys pulling labels ....
The yellow thing in 2, is that the one you mean? def a euphorbia, the little annual one.
If you're looking for a poppy try 3.
No not a poppy, its a spurge, if you google you will see the exact one.
The little pink white flower is what we call Ladies Tresses, not sure of real name.
Still dont know 3, not dicentra or aquiligia