Larryforehand

I have read the material on the home page and elsewhere. I am intrigued by the prospects of Unraid, but a bit overwhelmed at this point. Is there a tutorial that will take someone step by step through not only installation of software, but possible hardware configurations. I see in the adds, the possibility of even IDE and SATA drives being combined, but most cases, motherboards, etc. that I'm aware of do not have dual capability. I have a rather vanilla home network, T-Mobile home internet, TP-Link Deco Mesh system, 3 Pc's (windows 11), couple of tablets, and two D-Link DNS units, retrofitted with Linux operating systems, serving as RAID storage. My initial question is: all of the instructions mention "server". Do I need to purchase a rack mount enclosure or can an existing or additional ATX case be modified to function with Unraid? Also would I need to install server OS on one of the units? If these questions are answered somewhere on the forums or FAQ, please let me know