Got this poor little guy for free. Looking for help to nurse it back to health.

I got this little Echeveria for free from a large supermarket giving them away. It is obviously in very poor condition but I wanted to try to nurse it back to health. Ive grown many things but succulents are not one of them. Looking for advice on how I might give this little guy the best chance possible.

First obvious problem is they overwatered the crap out of them. Currently letting it dry out next to my Aerogarden so it gets plenty of light.