If you are new to Steam then follow these instructions to download the platform and activate your game
Step 1. Download Steam
If you do not already have Steam installed, go to the official website: here and use the button in the top right that says “Install Steam”.
Download the application/setup file and install follow the installation process. Choose where to install the software if you want to use a different hard drive for games etc.
Step 2. Create an account/Log in
Launch the Steam software and login or create an account if you do not already have one.
Creating an account is very simple. Enter your selected username, email address, etc. and verify your email address. You might also have to verify your selected computer/device.
Step 3. Activating Your Game
Once you have logged into your Steam account, go to the top menu bar where you see the options: Steam, View, Friends, Games, Help – and select ‘Games’, then ‘Activate a product on Steam…’
A new window will pop up for the product activation process. Simply click ‘Next’ and then ‘Agree’ to the terms and conditions of Steam activation.
Now we are at the product code entry stage. Simply copy/paste your activation code into the product code box and click ‘Next’. Steam should now confirm your product is activated and continue to the installation process.
The game will now appear in your games library and you will be able to play once the game has downloaded.