Hey there, I'm doing society and culture and also extension English
If your thinking of becoming a Journalist it would probably be best to do the top English you are capable of! Extension 1 is basically just a lot of in-depth studies of texts. You go through different genre type categories then at the end of prelim course as a class you pick one of the genre's to study for HSC. eg Romantics, After the Bomb or Sci-fi (there are about 12 I think)
Also extension English 2 is offered at the end of prelim, the whole course is basically just a major work and a small assessment; I'd look into that course to see if it's something you would like and be good at and that will help you decide whether or not to do extension 1 in yr11.
With Society and culture it is a lot of work and a lot of independent research! At the moment I'm doing the mini PIP, it's really time consuming and not even half of the major PIP! I'd recommend going into yr 11 knowing an area of topic you want to base your PIP on so as you can apply the research information to your topic as soon as possible!
Hope this helps a little