Gathering information on daily usages

Hello Experts,

I would like to gather information about our daily/monthly usages in Elastic. I did go thru the stack monitoring but not much information i get in there.

I am looking to have daily ingestion in GB, disk usages for the deployment and usages based on indices. (This one might available in Stack monitoring)

Also i try to change this to shows in GB instead of bytes. what command are accurate to change from bytes to Gigabyte. i tried /1024 but not working.

median(elasticsearch.index.total.bulk.total_size_in_bytes)

Appreciate yours input. Thanks in advance