I started TryHackMe’s Pre-Security path this week. It’s free, it’s the recommended starting point if you have no security background, and it’s structured as five modules that take you from “what is a network?” to “what is a vulnerability?”

I have a CS degree and six years of web dev, so I’m not a true beginner. But I wanted to walk through it from the start anyway, because two things were true:

  1. I haven’t thought about networking fundamentals in years.
  2. Skipping foundations is how people fail Security+.

Here’s how the first few rooms went.

Module 1: Cyber Security Introduction

This is mostly orientation. What roles exist (red team, blue team, GRC), what a SOC is, what penetration testing is. If you already have a sense of the field, you can skim it in 30 minutes.

✅ Worth doing if you’re brand new. ⏭️ Skip if you’ve already read any “what is a SOC analyst” article.

Module 2: Network Fundamentals

This is the heart of why I’m doing the path. The rooms cover:

  • The OSI model
  • TCP/IP
  • IP addresses, MAC addresses, DNS
  • Common ports

Even with a CS degree, doing the practical exercises — actually pinging things, looking up DNS records, identifying what port HTTPS uses — was useful. The terminal practice alone is worth it.

I caught myself rusty on subnetting. I didn’t fail any questions, but I had to think about it harder than I should have. I’ll come back to subnetting in week 2 of my Security+ prep.

✅ Worth doing slowly. 📝 Open a notebook. You’ll want to write subnet math on paper.

Module 3: How the Web Works

For a former web developer, this is the easy module. HTTP requests, status codes, cookies, what <script> tags do, basic injection ideas.

⏭️ Mostly skim if you’ve ever shipped a website. The key new content for security is around “what an attacker looks at” — same web, different lens.

What I’m taking from it

A few notes I want to remember:

  • The OSI model isn’t trivia. Every Sec+ question about which layer something happens at depends on knowing it cold. Memorize layers 1–7 and what runs at each.
  • DNS is more interesting than I gave it credit for. Recursive vs authoritative resolution, record types (A, AAAA, MX, CNAME), TTLs. There’s a whole attack surface here I want to come back to.
  • TryHackMe’s editor for typing answers is annoying but the rooms themselves are genuinely well-built. Don’t let the UI put you off.

Time spent

About 6 hours total over two evenings to get through the first three modules. I’ll finish modules 4 and 5 (Linux fundamentals and Windows fundamentals) over the next two days, then move to the SOC Level 1 path.

This is a good way to stay honest with myself about what I do and don’t remember from years ago. Recommended.