This site isn't a forum. There aren't "follow-ups" here: there are questions and answers. If you want to ask a question, use the Ask question button. If you know the answer to a question, write it in Your answer under that question. It doesn't matter how relevant it is: if it's not an answer to the question, it doesn't belong there. People who know the answer to your question won't see it if it's not posted as a question, and they can't help you, because you can't answer an answer.
Running the site in this format is what makes it a repository of information that's easy to find and navigate, without the problems of thread hijacking and "me too" posts that you get on a forum. It means that people who know about the thing you're asking about will see your question on the front page of the site: you're not relying on them looking on the n-th page of a thread about a related question that they're not going to look at because they already know the answer.
The tour is a really brief introduction to all of this. You get a badge for reading it, but more importantly, you also learn how to get your questions answered by experts.