Wow, I'm probably the "best"-qualified person to address someone not knowing much about computers. It didn't even occur to me that part of your confusion might be in thinking this was a real-time forum. The way to think of this that makes the most sense to me is to think of it as an
actual bulletin board, maybe in a hallway of a classroom
bldg., and people put up questions or comments, then come back by later to check for responses.

I haven't a clue what BBS is, either, or even "hot type".
The best advice I can give you is, when you make a post,
to go up to the top of the screen that has the window for you to write in, and click on You May Use markup in your post. This will give you a whole set of instructions which look complicated, but can't be all that bad if I can figure them out (as I eventually did,
with some kind personal instruction--thanks, tsuwm).

The other best piece of advice I have for you is to click on
the FAQ (frequently asked questions) button at the top of any screen.

If you want to respond to a post, click on the golden box
at the top right of that particular post, and you'll be given an "In response to" screen. (You can go to markup in your post from here, too.) Note: on your own posts, you should see a second golden box next to the one at the far right. Click on that one if you want to change or delete your post.