I bought this succulent a few days ago and noticed that it's stem is a bit browned, I'm not sure if it had received too much or too little water with it's previous owner, so I added just a few drops of water to the soil. At the end of day one of its leaves became shriveled and browned, I'm not sure what's going on. Please help!!

Before the drops of water:






After the drops of water:

The loss of leaves from the bottom of the rosette is normal and nothing to be overly concerned about, as long as they are being replaced by new ones growing at the top. As for watering, the best approach is probably to water well (until water comes out the holes at the bottom of the pot) and then wait until the soil is dry or nearly dry to water again. There is no particular advantage to leaving the soil bone dry for any extended period, though. Provide as much light as possible indoors (like right by a sunny window). Hopefully this helps.