What is EC2, Anyway?

Amazon EC2 (Elastic Compute Cloud) lets you rent a virtual computer in the cloud instead of buying physical hardware. You pick an operating system, a "size" (CPU/RAM), and AWS spins up a server for you — billed by the second or hour depending on usage.

Before launching, there are a few key concepts to understand:

• AMI (Amazon Machine Image) — a template that defines the operating system and pre-installed software on your instance.
• Instance type — the "size" of your virtual machine (how much CPU and RAM it gets). t2.micro and t3.micro are the free-tier-eligible starter sizes.
• Key pair — a security credential used to prove your identity when connecting. AWS gives you a private key file (.pem) to keep safe, while the matching public key stays on the instance.

Step 1: My First Launch Attempt (and a Real Error)

I went with a macOS Sequoia AMI for my first attempt, mostly out of curiosity. I created a key pair, configured the instance, and hit launch.

It failed with:

Instance launch failed
A Dedicated host for the specified launch parameters could not be found.

Why this happened

Turns out, EC2 Mac instances can only run on Dedicated Hosts — physical Apple hardware that AWS reserves exclusively for one customer at a time. This isn't an AWS limitation; it's an Apple licensing requirement. Unlike Linux or Windows instances, which share underlying physical hardware across many customers, macOS instances need their own dedicated physical Mac hardware, allocated for a minimum of 24 hours at a time.

Since I hadn't allocated a Dedicated Host, my launch had nowhere to go.

Step 2: The Fix — Switching to Amazon Linux 2023

Instead of provisioning a Dedicated Host (which costs real money, no free tier), I switched to Amazon Linux 2023 — a free, lightweight Linux distribution maintained by AWS — paired with a t3.micro instance type, which is free-tier eligible.

This time, the launch succeeded immediately:

Success
Successfully initiated launch of instance (i-07898b4cbb86ebe12)

Step 3: Connecting to My Instance

Rather than setting up an SSH client locally, I used EC2 Instance Connect — a browser-based terminal built directly into the AWS console. No key pair juggling, no terminal app needed. One click, and I was in:

Amazon Linux 2023
https://aws.amazon.com/linux/amazon-linux-2023

Last login: Sun Aug 23 08:00:29 2026 from 13.233.177.4
[ec2-user@ip-172-31-4-73 ~]$

Seeing that prompt for the first time — knowing it was a real, live server running in a data center somewhere — was a genuinely satisfying moment.

Step 4: Poking Around Like a Sysadmin

I ran a few basic diagnostic commands just to get a feel for what I was working with:

whoami
# ec2-user

cat /etc/os-release
# NAME="Amazon Linux"
# VERSION="2023"
# PRETTY_NAME="Amazon Linux 2023.12.20260817"

df -h
# /dev/nvme0n1p1   8.0G   1.7G   6.4G   21%   /

free -h
#            total   used   free
# Mem:       913Mi   159Mi  509Mi

uptime
# 08:05:13 up 29 min, 2 users, load average: 0.00, 0.00, 0.00

A few things stood out:

• 8 GB of disk, only 21% used — plenty of room for small projects.
• ~913 MB of RAM — a dead giveaway that this is a .micro instance (they're intentionally small, meant for learning and light workloads, not heavy apps).
• Load average: 0.00 — the server was basically idle, just waiting for me to give it something to do.

Step 5: Cleaning Up

Once I was done exploring, I went back to EC2 → Instances, selected my instance, and terminated it:

Instance ID: i-07898b4cbb86ebe12
Instance state: Terminated
Instance type: t3.micro

This step matters more than it seems. Forgetting to terminate unused instances is one of the most common ways beginners rack up unexpected AWS bills. Since mine was a free-tier t3.micro running for under an hour, cost wasn't a concern here — but it's a habit worth building early.

Bonus: AWS Free Tier Credits

While going through this, I discovered AWS's Explore AWS program: new accounts get $100 in credits at sign-up, plus the option to earn up to $100 more ($20 each) by completing five hands-on activities:

1. Launch an instance using EC2 ✅ (this one!)
2. Use a foundation model in the Amazon Bedrock playground
3. Set up a cost budget using AWS Budgets
4. Create a web app using AWS Lambda
5. Create an Amazon RDS database

Since I'd already completed the EC2 activity as part of this walkthrough, that's $20 down — with $80 more up for grabs. I'll be tackling AWS Budgets next since it's quick and doesn't require spinning up any infrastructure.

Key Takeaways

• macOS EC2 instances need Dedicated Hosts — a common gotcha for anyone experimenting with different AMIs for the first time.
• t2.micro / t3.micro are the instance types to reach for when learning, since they're free-tier eligible.
• EC2 Instance Connect is the fastest way to get into an instance without any local SSH setup.
• Always terminate instances you're not using — it's the single easiest way to avoid surprise charges.
• AWS actively rewards you with credits for completing basic learning activities, which makes experimenting essentially free if you stay within the guardrails.

What's Next

Next up: setting up a cost budget with AWS Budgets to grab another $20 in credits, and probably trying the Lambda activity after that to get a taste of serverless computing.

If you're also just getting started with AWS, my biggest piece of advice: don't worry about hitting errors. The Dedicated Host error taught me more about how AWS actually works under the hood than a successful launch would have.