Cultivation is not a problem if you have a 5 year old daughter.
She just loves to pluck the "fuzz balls" and scatter the seeds by blowing on them.

If you don't have one of these just borrow your neighbors and viola soon you will have your very own dandelion patch.

I am not a fan of dandelions. I find them too bitter even if the leaves are picked before the flower buds start to fill out or the flower stalk starts to rise.
The older people here like to use the early leaves off them in salads much like the wild lettuce leaves, which I find bitter to.

I do like lamb's quarters (chenopodium alba) though. It is much milder and is better than spinach when it is young. A related plant which is often red and is known as Orach is often grown as an ornamental/salad plant in gardens

Another OK weed for greens is wild mustard. The young leaves can be used like spinach for salads, cooked and the seeds can be ground to make hot mustard later in the year. Mustard greens cook up mild like beet tops or collards.