Hi, what I'd suggest you is to utilize the eventhub channel and subscribe to block events as a start. Regarding peers that joined the network - right now that's not possible to list the peers in the network by querying a peer.
a possible alternative of visualizing the interaction between Hyperledger Fabric network entities might be to use weaveworks. It creates an application map based on the interaction between Docker containers, allows you to monitor and understand relations.
hope this helps