Very well worded.
You WILL need a home lab for this. Not having the experience of a network engineer or at least a couple of years of IT experience is going to mean learning a lot of new things for the first time and a lot of memorization.
If you can get your hands on a managed switch that supports VLANs and a real router, you can learn about the challenges with multiple VLANs, how to provide DHCP to clients in each VLAN, the security gained from segmentation, and this sets the stage for adding a firewall. This type of environment is the beginning of what you would see in a corporate environment. Don’t skimp on the firewall either, get a good one. I use OPNsense. All of this is just on the network side.
For security, the first thing to learn is how packets move through a network (I know, this is part of the network portion, but it is the basis for security). Next is to learn how applications communicate (IP and port numbers). Net+ and Sec+ will cover this. Next, get into NMAP and learn how to scan a network for live devices and what OS they are running. From there, I would suggest picking a couple of good security tools like Nessus or Geenboone’s OpenVAS. These are vulnerability scanning tools. Once you get comfortable with that move to pentesting and learn to use tools like Metasploit. These are all practical skills to learn, there is a huge amount of learning to go with this, like policies and procedures, NIST, what CVE means and how to read the scoring. Try to keep things as simple as possible as cyber security can get very complex. In the end all of cyber security is about two things: Identifying and mitigating risk. It’s all about risk.
Mike Myers has one of the best Net+ books, plus he has a very good course on Udemy for Net+ and Sec+. For Sec+, I used Darrill Gibson’s book and Mike’s Udemy course.
Download the exam objectives and build your self-study from there.
Good luck and post questions here (or PM me if you want). I’d be more than happy to assist you with Net+ and Sec+. Security auditing is beyond my expertise, though.