Looks like Ludwigia peruviana, Water Primrose. Its a shrub that gets yellow flowers. It is native from Mexico to Chile and Uruguay. In Florida it it is considered an invasive exotic. It grows in shallow water and wet locations. In cultivation it seems short lived (just a few years). If you are in an urban area it can be cultivated as it attracts butterflies and other pollinators. If you are adjacent to natural areas I would remove it. But it is rather entrenched in the southeastern US so it has become a new "native".

I live in South OC, with sandy, nutrient poor, soil, so our growing conditions are likely fairly similar. My army isn't an orderly group; I've used the plants as structural contrast in various parts of the garden. Although I am working towards filling in some to form groups, that is a work in progress as I find plants offered that are more in my price point (the prices have almost doubled since I bought my first). Mine are all in-ground, and they seem adapted to whatever watering the surrounding plants get. Some individuals started blooming about 3-4 years in ground, but others have not yet. Delays might be due to the poor soil, or that some have a bit less sun due to trees that have grown and now block some light mid-day. After bloom, the flowering one very, very slowly declines, but basal plants take it's place, so it is not missed when it gets removed. I had both the variegated 'Flamingo' and the regular bloom this past spring and the difference in the flower stalks' color is noticeable. Not a great photo, but Flamingo is the pinker one in front, and you can see the less colorful species one just behind the white echium flower stalk. The species one is a basal plant that is blooming, from the original plant that bloomed in 2016. I also grow B. albiflora, which has more of an agave form and seems to prefer a little more sun protection and more water), and had B. wrightii, which I unfortunately lost after it flowered.

Thank you Carol- i will look up the names you provided as it is alway nice to discover new plants. i was buying small celery plants when i spotted it next to the Parsley. -i did ask for the name, but i didn't write it down (it was not a herb that i had ever heard of) but i was told it went in pies. i thought it looked like Burnet. possibly some flavour will develop later -so far it just tastes fluffy :-(

Water thoroughly when dry. Let water run out the bottom holes. Never by tablespoons. You can tell when they need water by inserting a wooden skewer for a few minutes. When you remove it, if it’s damp, don’t water. As for the third pic, I suspect the pot is too big for them, and they should be potted a little higher if you are able to repot in a smaller container. The recommended soil mix here is commercial cactus and succulent potting mix combined 50-50 with perlite available from your nursery. You are on a good start with your succulents. I suggest you take time to read many other threads here, and you will learn a lot. Also there are some good YouTube videos. I like Debra Baldwin, another is Sunshine and Succulents.