What version of firmware is your R500 running?
If your firmware isn't the correct version, the AP won't automatically connect to the Ruckus Cloud service.
Unleashed as mentioned by Abi, is a separate firmware train from standalone, Cloud and SmartZone and is intended for centrally managed deployments of APs without a controller appliance.
I would recommend installing the latest version of Unleashed firmware or the R500's standalone software, currently version: 22.214.171.124.675.
This support page might help: https://support.ruckuswireless.com/articles/000005720