Analysis on the Data Usage in Elastic

Hi Elastic Community,
I need some guidance in analyzing the data usage in the Elastic Tool.

My first objective is to fetch the daily/weekly/monthly data usage.
My second objective is to find how much data is sent to the Elastic Cluster by each Elastic Agent.

Things I have implemented so far:
-Using Elastic Dev tool and running the query in the console
GET/_cluster/stats?human&pretty

-Using the following query GET/_cat/indices?v&bytes=b to fetch the Data Usage by indices.

I request the Elastic Community to guide me.

Have you setup Stack Monitoring in kibana?

If not, that gives you quite a lot of visibility on its own.