Sure! For me, I go to the category I want.(Categories are the various sections of this forum. They’re indicated by those colored boxes under the thread title. For example, this thread is in both the Audios and the Sapien Medicine categories.) You can find the list of categories by clicking on that “hamburger” icon (in the upper right corner of this page that’s 3 horizontal lines stacked one on top of another) and that menu will show you a list of the available categories.
Select the category that best fits the topic of you thread. You select the category by clicking on it. That takes you to the category page.
At the top of the page, there’s a big rectangle box which reads “+New Topic”. Click in that and write your post. Easy-peasy.
If you’re writing about an existing field, chances are really good that there’s already a topic created for that field. It’s good practice to write your post in the already existing topic of that field. It keeps the forum organized and helps our future forum friends to find your discussion more easily.
Just write a post in the threads that you want to be involved in. You already know how to do that. (Yay, you!) So, do as much of that as you want. Have fun!