Second one:

Last one:

First one looks like a wild buckweed seedling
second looks like smartweed seedling
third may be dames rocket seedling......

Hmmm... I didn't plant any of those....

So that means all the seedlings I thought I had growing from the seeds I did plant are not growing. :/

The weird thing is these are growing in big clumps just like the seeds were sowed.

Not that weird. You prepared a nice clear patch of cultivated soil. Weeds are opportunists and they move in fast. They are weeds for the very reason that they are good at finding a conducive place and growing fast.

The earth there looks rather cracked so I'm suspecting there is a bit of crust on it. That would deter your seeds from growing.

You hit it right on the nose with Dames Rocket. That's what it is. I remember those from last year - the previous owner planted those. I'm leaving some of those since they are actually kind of pretty but I removed everything else so I can plant things I like myself.

Thanks for the help!! I think this winter I will start seeds inside. Much less stressful.