Currently there is only 1 project stored into this repo, the mysql-event-logger. The project consists of 2 key componets 1) The REST server 2) The Smartapp. To get data from SmartThings into MySQL you need both (you can set them up in any order, but if I had to suggest one I'd start with the REST server).
Review the README.md files in each folder for more detailed instructions on what to do next.