Hello, welcome!
Glad you discovered the Ghost integration, it ties in quite nicely with Mastodon etc.
If you have any specific questions or want help with anything please feel free to ask! There's also lots of help for new people on the website at https://fedi.tips
About how this place works, I've tried to do a straightforward non-technical summary at https://fedi.tips/what-is-mastodon-what-is-the-fediverse