Whew! As a Saylor staffer, I'm always happy when the introductions thread gets a bit away from me. Welcome all!
I think everyone can benefit form a couple quick thoughts on @Wordsgood95's questions.
No. Or yes...up to you! Some course have specific discussion prompts. That is why ARTH101, for instance, shows up often in these forums. But people are free and encouraged to start their own conversations about courses -- to raise questions, to respond publicly to their reading, etc.
The best way to do so, at present, is to start a new topic and choose the appropriate category and, if applicable, a subcategory. Make the title of the topic something fairly specific...For HIST103, the category is Courses and the sub-category is History. Putting the course code in the topic title is a good practice (although we may get into using tags one of these days). In fact, here is a live example post I just made.
Eportfolio is a strange beast, and some changes are on the way. We had once meant to build more social features into eportfolio -- the ability to follow or favorite others' profiles. We also have considered eportfolio to be one way to display your work and certificates to an employer or whomever. For those reasons, it was important to let people make their profiles fully private, public only to other students, public by link only, or fully public. Discourse, then, is really taking over the social aspects of eportfolio. Because Discourse is public-only, we wanted to allow people to use a nickname and have the freedom to participate in discussion on their own terms.
The question of how to use Discourse to its fullest as a tool for social learning is probably worth its own separate discussion, possibly in the Meta category.
Enough writing for now! Welcome again to all