Raspberry Pi, N100 mini PC or a used office desktop: pick your first always-on box by RAM, storage, idle watts, noise, network ports and software support.
Count the powered ports, budget by class at the switch port, insist on SNMP if you graph things and keep it fanless. A home lab PoE switch, worked through.
Measure the load, check it against both the watt and VA ratings, read runtime off the maker's chart, and know when pure sine matters. A worked example included.
A UGREEN NAS gives a home lab more CPU, RAM and M.2 slots. A Synology NAS gives it DSM, SNMP and mature backups. How to choose, and how to watch either one.
VLANs, mirroring, LACP and SNMP: what a managed switch adds to a home lab, why many budget models cannot be polled, and how to pick ports, PoE and cooling.