No worries, thats why we are around for.
Start using this command:
ee site create yourwebsite.com --mysql
It will return usefull information regarding your MySQL created user/database and your newly created domain. Save them, you will need them.
Now navigate to /var/www/yourwebsite.com/htdocs/ and paste the following:
A newly created folder, named 'wordpress' will appear.
Feel free to delete the latest.zip file and rename 'wordpress' to your preferred subdirectory name.
Now, there is a harder part. The one that needs a rewrite rule for your subdirectory.
Edit /etc/nginx/sites-enabled/yourdomain.com file using nano (or your favorite text editor) and add the proper code for the subdirectory rewrite.
This URL might help you: https://github.com/EasyEngine/easyengine/issues/31
Now, you need to reload nginx's saved config. Use this command: service nginx reload
Once you do so, visit http://yourdomain.com/yoursubdir through browser and start the famous auto-installer of WordPress.
You will be asked for credentials of database. Enter the previously saved ones and voila, everything should be more than fine