you canno use only one centrilezed console to manage Splunk infrastructure, you have to use more servers:
So you have at least to use two or three servers for your monitoring consoles.
You can find these indications in Splunk docs in every section (Indexers Cluster, Search Heads Cluster, Deployment Server):
Forwarders are managed at Settings->Forwarder Management on your Deployment Server (DS).
Data retention is managed at Settings->Indexes in a standalone environment or in indexes.conf on the Master Node (MN).
Both DS and MN can be on the SH instance, but this is not best practice.