#1 A weedy Campanula such as C. rapunculoides.

#2 Likely Lotus corniculatus - Bird's-foot trefoil.

#4 Taraxacum sp. - Dandelion & Plantago sp. - Plantain.

#5 Trifolium repens - White clover.

#7 Centaurea cyanus - Annual Bachelor's button.

The tree is a Basswood, Tilia species. Sometimes called Linden. I think the last pictures is the same thing, looks like the branch broke off while it was in bloom and the flowers dried up?

#2 might be Field Bindweed, cousin of the Morning Glory vine. Highly invasive.

I have Linden trees. Lots of shade, smell wonderful, but 1000 little seedlings come up every year. Good luck!

6/8 - Given what I see, I'd say Tilia americana over an European linden.

And I agree that #3 is Lotus corniculatus.

And lots of other stuff in #4. I also see ragweed and black medic. All pretty common stuff in an untreated lawn.

Thank you very much everyone ^_^