All kinds of “weeds” in those pix. But, I’m pretty confident based on pix in No 2 that those small roundish flowers are not clover. I don’t see any clover leaves there at all.
I use the app "Picture This" which has been very reliable in giving me the name of the weed, which I can then investigate further, if need be. I took pictures of your pictures and it came up with Aligatorweed a species of Joseph's coat for the little flowering plant in the bottom picture. It is in the Amaranthacea-Amaranth, Goosefoot family. The top picture's primary flowering weed came up as Devil's beggarticks aka Bur Marigold, Pitchfork week and Sticktights it is in the Asteraceae-Daisy family. Both considered invasive weeds. Both are considered Herbs. Nothing mentioned about them being dangerous. Good Luck!