Homelab

Hi!Relatively new to network stuffs, please forgive the lack of terminology.

The situation is as follows:

I have an old PC that I have reused as a home server.It currently runs my Plex and network share, and hosts a few private projects locally. (In Windows environment... Noob setup, just followed the LTT guide, miserable, I know)I know the very basics of virtualization, have also played around with Proxmox on the server, still have it installed, but so far not much progress in learning it.However, I want to make some parts of the server accessible publicly for very small-scale private web project hosting and general learning about hosting/self-hosting, networks, development, security, etc.

I was on a dynamic IP provided by the ISP. I could manage workarounds for changing IP addresses, but, in any case, port forwarding on my router doesn't work because of how the ISPs infrastructure is set up, so that kind of screwed with things.After a long conversation with my ISP, they now provide me one dynamic IP and one static IP (with no additional cost, in fact, my monthly bill will now be 10 cents lower!)I want to use the dynamic IP for my private LAN, and the static IP for the public parts of my server.Reasoning goes that I don't want my whole entire private network sitting on a static IP.

However, they don't provide two physical access points - all traffic goes through one single fiber optic network cable that comes into my house. It then plugs into a device that my ISP set up and I have no knowledge of, other than the name - Huawei EchoLife EG8010H.From it I ran a cat5 cable to the input of my router - TP-Link Archer C1200. Currently all my network devices are connected, via cat5 or Wi-Fi, to this router. Including the server.

Desired result :

Essentially, I want to move some functionality running on the server out of my LAN to it's own static IP. However, there are certain parts of its functionality that I'd like to keep for internal use only (like Plex and LAN share). I know I will, at the very least, have to set up separate VMs for functionalities that I want to keep on separate networks. Also, in the future it's likely that I'll want to make more devices accessible publicly (private IoT projects), so I assume I will also have to have another router running on the static IP connection.

Obviously I have virtually no control over the ISPs Huawei device. However, they told me that in place of my router, I have to connect a network switch, and then run two cables from the switch to two separate routers. When that is done, I should call them and they'll do some kind of setup. I gathered that it's related to MAC addresses.

So eventually, I gather, I will run two networks -

1. My LAN on a dynamic IP
2. Public stuff on my server and other devices on a static IP.

Vaguely worded questions for lack of more knowledge of things and terminology :

1. Is plugging a switch between the Huawei and two routers, and some configuration, really all that's necessary? Does it work like that at all? Wouldn't a malicious party be able to cross through the static IP connection into my LAN via the switch?
2. Do I have to look for anything specific for the switch, DHCP support or anything like that? Are there any other pitfalls that I don't yet know about or might have missed?
3. To keep the private parts of the server private, do I install another network card in it, then run a cable from the router that is going to be configured for dynamic IP, and configure the VMs to be accessible only via that network interface? Is it possible and is it safe? Would it be better/safer to run a separate dedicated machine for public hosting, entirely apart from my home server?

Final thoughts :

How can I learn more about networking, security, servers, virtualization, hosting, all these related questions? I find it hard to come by any materials that could help me extend my knowledge. Mostly I see either basic information that assumes you know basically nothing, like explaining the difference between IP and MAC addresses, or skimming the surface of how DNS works, or really advanced things where I'm completely lost and out of my depth, like subnetworks and IP address maths. It feels like all the intermediate knowledge is either so common that nobody really talks about it in a constructed manner, or is locked behind some school or key that I don't know about. I've tried to also study the wiki here, but to me it just looks like what it is at face level - a list of hardware and software with some generic description about it's functionality. It does not help me understand how the underlying dependencies work together to make a working system. It does not help me learn the best practices of structuring a network, or server virtualization, or security.

I've spent many-many years as a Windows power user, since Windows 95. Worked at an ISP (not the one in question here) as a assistant technician for a time, spent a lot of time providing all kinds of user and tech support, with which comes a lot of dealings with all kinds of hardware also, computer hardware, network hardware, peripherals, electronics repair, etc. Coming up on 5 years of experience also as a software dev. So I've definitely been around and seen some stuff, but haven't branched out really into the networking and servers realm. Recently decided to gradually move away from Windows, hate the direction they're going, and started to embrace Linux and FOSS. And I feel the same lack of finding any form of consistent and constructed knowledge also in the Linux realm - it looks like people just assume that you know things.

Is the way forward just playing around, stepping on all the rakes and dealing with the bumps as they come? I fully assume, of course, that my lack of finding new information might be based on some basic knowledge that I'm missing. Is there maybe a "roadmap" that could be used to guide someone on the networking journey?