Hardware

The hardware requirement for a home lab can depend on your needs, but generally any machine with the following minimum specifications will suffice for a linux server:

Four cores and four+ threads
8 GB of DDR3 ram
256 GB of Solid State Storage
Hard Wired Connection
Static Local IP address
Port 443 accessible from WAN (Not blocked by Internet Service Provider)

In addition, you want a comptetent router to handle the traffic and requests to your server. If you plan on using a Cloud Virtual machine, or VPS, this is irrelevant.

A competent router is one that meets the following criteria:

Latest WiFi Standard
2 GB of Ram
1 gigabit networking for WAN and LAN
Reputable Security
Port Forwarding Options
Customizable Network Address Translation