I am new to Super User and not familiar with all questions. Is it possible to follow specific topics/tags so that I can see only them in my questions/newsfeed?
Yes. You can set up a list of "favorite" tags. Click the "edit" link under the Favorite Tags heading on the right of the main site's homepage; there you can add and remove tags as your favorites. Here's what mine look like:
Once you add some tags and reload the page, questions with at least one of your favorite tags will get a blue highlight.
If you want to see only unanswered questions with your favorite tags, go to the "my tags" tab of the Unanswered page.
If you want an RSS feed of a given tag's questions, go to the tag page (click the tag; here's the [windows] one as an example) and scroll to the bottom. You'll find a link to a feed with the tag's newest questions.