Can you buy any gardening? Anywhere from soil, seeds or starter vegetable and fruit plants?

Yes there are at least 2 large garden stores on the premises

There is a nursery across from the Farmers Market. I believe on weekends they might have a few vendors selling flowers.

They sell plants on the weekends, at the front of the Shed. There is also a compost company on the weekends!

There is a plant nursery next door to the market.

There is a garden center right by the farmers market called Rubials

I have not see any of those items when I have gone.