I found the Cisco free networking courses really helpful when trying to figure out my network stack. Some of the earlier stuff you probably know but you can skip through quickly, especially if you don’t care about getting the “qualification”. https://www.cisco.com/site/us/en/learn/training-certifications/training/netacad/index.html

I would personally recommend keeping the router and adguard/pihole server separate. If you mess something up, it’s easier to quickly switch the router DNS to a public one whilst you try to fix it, especially if you have anybody else at home who won’t appreciate losing their internet because you messed up something (which will happen but let’s you learn)! It’s also a good idea to keep this separate from your main server for this very same point. You might accidentally use up the entire hard drive or have some messed up update on one software take all the RAM, making everything else unusable (both happened to me at different times, and one was overnight before I was working from home which was not fun to try and fix first thing in the morning!). It’s not always clear which device is causing and what went wrong so can take some time to fix but gives you flexibility to fix in your own time.

That’s why I would recommend getting a used thin client for £30ish (GBP) from eBay or somewhere like that. I have my pihole and home assistant on there to be clean and separate in case my server goes down. Then the internet still works, the lights still work, and things like nextcloud and jellyfin just have to wait a bit.

It also allows you to upgrade devices separately (e.g. when my internet provide unexpectedly upgraded to 2.5G I chose to buy a new router and one of the switches, and upgrade the Ethernet socket on my home server) but kept my existing WiFi access point and pihole/HASS server which still work fine after years of use. Most of my clients at home can’t handle higher speeds so no point upgrading the rest of the network until they can (if ever). I have separated my WiFi access point and router because of the location of my incoming wires and home layout, which you could also think about doing. I’ve always thought getting seperate devices focusing on one thing they do best makes sense, and can actually be cheaper to buy.

Not sure about routers themselves but have heard good things about openwrt. I do NOT recommend the TP Link Omada series!

Please nobody buy roku. It’s become full of ads and monitoring.

No IT formal education, training, career or any job here. I’m an accountant by day and this is all a hobby for me, allowing me to save on subscriptions and having complete control of my family’s data