This weed is (in my opinion) the Thistle. Highly invasive and very difficult to control if its flowers are allowed to stay and mature. The flower pods when mature open up and sends out hundreds of seeds attached to a fluffy white plume like thing, which when carried by wind will establish itself as a new plant.

Oh gracious! Thank you so much. I have been pulling them up before they bloomed, but I will be out there getting the rest of them up tomorrow! Thank you so much for the information!

Donna, there aren't any thistles in any of your pictures. The pink flowered plant is an Evening Primrose, Oenothera species. Not a weed.

Great. Thank you so much. I haven't had time to pull them up, so they're still out there!! Whew!!

Although native in N America, not a plant I would allow in a tended garden, spreads way too fast.

Well, there's also Oxalis and Red Dead Nettle in the pictures, so on balance I'd take the Oenothera ;-) If the OP wants a ground cover and has space I can't see much objection to it. It is sold for such a purpose. Oenothera speciosa

"If the OP wants a ground cover and has space I can't see much objection to it" No doubt. And agree they are very pretty, just not the kind of team player I cultivate and I get my fill of them driving by uncultivated areas. The OP says "in my garden..." As far as opinions go, all of the plants in the pics (except the bulb that belongs to the long blades in the 2nd pic) would be composted @ my house... as I obtain/propagate other plants to take the space.

Everyone likes different things. I have intentionally planted evening primrose as I have a large area that can handle it. It can always be knocked back. It can be aggressive as can many other plants, but it does depend on your location and needs. For example, I dislike yarrows of all types, because they itch (or at least I'm allergic) and they are aggressive. To each their own demons.

Definitely. I don't keep plants that garden on their own, when I'm not around. If there's any spreading, it'll be because I did it, or allowed seeds to form.