You can pick up an old NUC for £140 on ebay. So 4GB RAM, 128 SD disk, Intel i3 Core.

• Verify hardware – a mini server with a minimum of 2GB of RAM and 60GB disk
• Downloaded Ubuntu 20 which is current – ubuntu-20.04.3-live-server-amd64.iso
• Plumb the ethernet port into the router (Virgin Media Hub)
• Create USB drive (I used balenaEtcher on Mac), and install it with defaults
• Login and install Apache
• Obtain a domain and add to the DNS the hub router for a subdomain e.g. www.example.com
• Program Virgin Media Hub to forward port 80 and 443 to the this server
• Make the NUC a fixed IP using the Virgin Media Hub
• Install WordPress

Note on Virgin Media: only a business account give you a static IP but as the hub IP hardly ever changes its going to be good enough for this home server. However it needs you to also program the Hub to forward incoming ports to this server.