We been on Sensu Go but Discover there has been a Legacy Sensu Classic Env and now need to know

How to list all the configure host in Sensu Class

CPU and Memory each host have

Configure monitoring or Check for each host.

Once we have the info , we can get them decom or move to the Supported Version of the Sensu.

Please let us from where we can get as no prior exposure of the Sensu classic.
We have acces to the Sensu Classic UI and most proberly the Sensu servers at the OS level.