What are you planning to do with this storage server and how will you back up all the data? You asked a pretty basic question on attaching all those drives so I’m assuming you don’t have much experience with storage servers.
You don’t want this server to be the only source of your important data. I will just point you to the basic articles and posts. If you already know that, just skip it.
Stick to CMR and not SMR hard drives
SMR vs CMR ServeTheHome
BASICS
iX Systems pool layout whitepaper
https://www.truenas.com/solution-guides/#TrueNAS-PDF-zfs-storage-pool-layout/11/
Special VDEV (sVDEV) Planning, Sizing, and Considerations