Kali Linux for beginners: installation, first steps and basic commands

This Kali Linux for beginners guide takes you from download to your first commands: how to install it safely in a virtual machine, what to configure right after booting and which basic terminal commands you need to master before touching any hacking tool.

What Kali Linux is and what it is for

Kali Linux is a Debian-based distribution, maintained by OffSec, designed for security audits. Its big advantage is that it comes with hundreds of pentesting, forensics and reverse engineering tools preinstalled, organised by category in the menu.

What Kali is not: a system for daily use, or something that turns you into a hacker just by installing it. It is a toolbox. If you do not know Linux or networking, learn the basics first (we explain how in how to learn ethical hacking from scratch). A very similar alternative is Parrot OS; you can see others in the operating systems section.

How to install Kali Linux: options for beginners

Recommended option: virtual machine

To start, install Kali inside a virtual machine with VirtualBox or VMware Workstation. That way you do not touch your main system, you can take snapshots and roll back if you break something, and you keep your lab isolated.

1. Install VirtualBox or VMware on your computer.
2. Download the prebuilt virtual machine image from Kali's official website (kali.org), in the downloads section. Always download from the official source and, if you can, verify the SHA256 hash they publish.
3. Import the image into your virtualisation software. Give it at least 2 GB of RAM (4 GB is more comfortable), 2 CPU cores and a minimum of 20 GB of disk.
4. Boot the machine. On the prebuilt images, the default username and password are kali / kali.

Other options

• WSL on Windows: Kali is available for the Windows Subsystem for Linux. It is lightweight, but some network tools do not behave the same as in a virtual machine.
• Live USB: you boot Kali from a USB stick without installing anything. Handy to carry around, less practical day to day.
• Bare-metal install: only if you know what you are doing. For learning it offers no advantages and carries more risk.

First steps after installing Kali

1. Change the password

passwd

The default password is public. Change it even if the machine is only for your lab.

2. Update the system

sudo apt update && sudo apt full-upgrade -y

Kali is a rolling distribution: it is updated continuously, so it is worth doing this often.

3. Take a snapshot

With the system clean and updated, create a snapshot in VirtualBox or VMware. If something breaks, you go back to it in seconds.

4. Check the virtual machine network

NAT mode is enough to browse and connect via VPN to platforms such as TryHackMe or Hack The Box. If you set up local vulnerable machines, create an internal or host-only network so attack traffic never leaves your lab.

sudo openvpn my-file.ovpn

That is the typical command to connect to a practice platform's VPN using the file you download from your account.

Basic Kali Linux commands you should know

Kali uses Zsh as its default shell, but the commands are the same as in any Linux. These are the essentials:

Navigating and managing files

pwd              # where am I
ls -la           # list files, including hidden ones
cd /etc          # change directory
cat file.txt     # show the contents
cp, mv, rm       # copy, move, delete
mkdir notes      # create a directory

Searching

find / -name "*.conf" 2>/dev/null   # find files by name
grep -ri "password" /var/www         # search text inside files

Users and permissions

whoami           # current user
id               # user's groups
sudo -l          # what I can run as root
chmod +x script.sh

Understanding Linux permissions is key for privilege escalation later on.

Network

ip a             # interfaces and IP addresses
ping -c 3 10.10.10.5
ss -tulpn        # listening ports on your machine

Packages and help

sudo apt install seclists   # install a package
man nmap                     # a command's manual
nmap --help                  # quick help

To practise all of this in a fun way, the OverTheWire wargames (starting with Bandit) are perfect. And if you prefer a book, Linux Basics for Hackers is written for exactly this point.

Your first tools in Kali

Once the terminal no longer scares you, start with these: Nmap to discover services, Wireshark to see traffic and Netcat for manual connections. The full list and recommended order are in the best ethical hacking tools for beginners.

Remember: use these tools only against your lab or authorised platforms. Scanning other people's networks without permission may be a crime.

Frequently asked questions

Can I use Kali Linux as my main operating system?

You can, but it is not recommended for beginners. It is designed as a working environment for audits; for everyday use a general-purpose distribution with Kali in a virtual machine is better.

How much RAM does Kali Linux need?

For a virtual machine with a desktop, 2 GB is the practical minimum and 4 GB feels smoother. Your host machine needs enough memory for both systems at once.

Is Kali Linux legal?

Yes. It is free software with legitimate uses. What may be illegal is using its tools against systems without authorisation.

Kali or Parrot OS?

Both work for learning. Kali is the reference in courses and documentation, so you will find it easier to follow tutorials with it.

If you want to learn to use Kali with a guided route in Spanish, we are preparing Ethical hacking from scratch ("Hacking ético desde cero"), a beginner course in 8 modules. The launch price will be 29 € (49 € afterwards) and the waitlist is already open.