You're currently connected to a Pinot controller, which handles the cluster-wide coordination for all Pinot nodes. Most humans tend to find the following features useful:
A place to conveniently run queries on the Pinot cluster. This is meant to be used for debugging, production queries should be sent directly to the appropriate brokers, to avoid having the controller forward the query to the broker.
An interactive documentation for the Pinot REST API with a swanky Swagger-generated page. Keep in mind that your actions here will directly affect the cluster, so be mindful of other tenants.