Array or Pool(s) - What is best for mainly Data Storage and Network Backup

So for a clear picture of my needs and understanding. In the past I have run all flavours of Windows Home Server until it became unsupported.  My main aims in setting up a Unraid server are:- 

Storage of recovery backup data mostly consisting of:-

A. My Audiobook collection

B. My Calibre Ebook and Documents Collection

C. My Music Collection 

D. Running a hobbists Web Server hosting several Wordpress Sites for development (available on the internet remotely etc)

C. Learning about using other OS`s by installing in VM`s

E. Curiosity perhaps in installing, exploring and using other applications.

I have set up my system with 2 drives in the Array (Parity + 1),  a SSD chip as a cache and the remainder 14 drives in a single pool.

I have watched a number of Unraid instructional videos on utube, mostly the excellent Spaceinvader One productions and gained a huge insite into the workings of Unraid, however,

I have become confused as to whether I should be using most of my drives in the array or in a single pool or multiply pools given my requirements to backup a large amount of data which is scattered amongst a number of drives both internal and external across 3 networked Windows 10 & 11 machines.

I seek advice and direction as to what my best/suitable data storage configuration should be. I have already backed up some data using windows based FreeFileSync but am happy to re-start my setup if needed.