Nginx is much more performant and better optimized for handling the type of workload Ghost has. You’re free to use Apache, but the support you get will be more limited as it’s not part of the recommended stack.
Ghost and Wordpress are 2 completely different platforms. Wordpress runs on PHP, and most shared hosting servers are configured to work with PHP. Ghost, on the other hand, runs on NodeJS, which most shared hosting servers are not configured to work with. The languages are fundamentally different, so it’s not really fair to either platform to compare them. Additionally, Ghost and Wordpress are built for very separate tasks.
Just FYI, while running Ghost on AWS isn’t much more difficult than running it on any other VPS provider, this is technically the hardest way to get Ghost - The easiest is signing up for Ghost (Pro), and the other method is to use the Digital Ocean One Click Install
If it’s inactive, you should just need to enable it. To do so, first make sure you allow ssh (otherwise your connection will be dropped) by running
sudo ufw limit ssh and then enable it by running
sudo ufw enable