You can download the latest public version from spigot, or download the latest dev version from this amazing website.
Public builds are the latest stable versions of the plugin. They should contain as few bugs as possible and overall provide a relatively headache-free experience to server admins and players alike.
Dev builds are the latest version to come out of the oven. They contain new incomplete major features, experimental bugfixes and all the fun oddities that accompany those two.
If you do opt to use a dev build, I seriously recommend you join my development discord channel. You can report any issues you may have there and expect me to answer as soon as I am available, as well as have live troubleshooting.
World downloads are currently only for getting the Adventurer's Guild recommended map. Soon, it will also include the various dungeons.