Please feel free to create new topics, as these are the equivalent of creating a new Facebook post.
There is a guide how to do this is in the User Guide, Settings, & Suggestions section of the Forum home page.
You will also find an Overview Of The Main Forum Home Page there to help you get used to the layouts.
There may be a learning curve getting used to the way things work, but you will find there are many features familiar with Facebook, such as auto video embedding and file attaching to topics (posts) and comments.
And all members have the ability to message each other privately as per Messenger. Simply find the member under the 'Members' tab and you can 'Send a Message' from there.
Any issues add a new topic in the Technical issues section lower down this page. Please bear in mind though currently I am a one-man-band 🙂