I am thinking about building a Pi-hole. I am a novice user (but tech savvy) and have never used a Raspberry Pi. There seems to be a lot of questions on the forum, therefore I wonder if a Pi-hole is difficult to use or maintain.
For one or two people on the network (maybe 4-6 devices: TV, Xbox, phone, laptop), would the 2GB version be satisfactory as a Pi-hole? There are some discussions about running out of RAM, so that might be a concern.
Does a Pi-hole run as a standalone device on your network or can you use it as a microcomputer for some mild multitasking (while it Pi-holes; I know it would need more RAM)?
Is a pi-hole better than using the AdGuard DNS server? I like the idea that it would be my own device on my network.
Pi-hole is quite resource efficient.
As far as DNS operation is concerned, even low-spec hardware will suffice.
Of course, Pi-hole's web UI will be more snappy with a stronger CPU, more RAM and faster storage.
2GB is very comfortable. And if you were referring to an Rpi 5 - that would idle away its time with just Pi-hole for a network your size.
Pi-hole will run on a 1st gen Zero with 512MB RAM without quirks, which is how I managed my own network (similar size as yours) for quite a while before switching to a NanoPi Neo with 256MB (yes, less RAM, but 4 cores - I made the switch as the NanoPi has ethernet on board while being fast enough to saturate it when serving Wireguard connections (running WG next to Pi-hole), and it even uses less power than my Zero).
Being resource efficient doesn't mean that you can't stress out a Pi-hole, but your typical home network won't get anywhere near its DNS limits.
Another area would be the overall size of your blocklists - if you pump every available blocklist into your Pi-hole, storage as well as RAM requirements may exceed what a Zero can handle. But then again, the default blocklist is already a good start, and I found that the Zero (as well as the NanoPi) was still capable of handling my additional lists, totaling at about 800k entries.
That's entirely up to you to decide.
But if you have any questions - we'll be here to help.
Pihole is a great project to dip the toe into linux / home servers. You can learn a lot from deploying it and maintaining it. I would recommend installing it on bare metal ( pi itself ) as opposed to something like docker. While nothing wrong with docker it will add a layer of complexity to it and if your new to it, baremetal install is much simpler to install and update.
Baremetal just means installation on the Raspberry Pi itself as opposed to something like Docker which is pihole running inside a virtual enviorment ( container ).
Baremetal means different things to different people.
However, your explanation describes how I run Pi-Hole on a RPi Zero 2W with an OTG Ethernet adapter using PiOS 64bit Bullseye, headless, with CLI and no GUI.