there is the major work which you will have to manage alongside your other subjects, but other than that, go for it! you can always drop it later if you don't like it. I do ext 1 and I honestly regret not picking up ext 2. I will say though, at my school the ext 2 major work was due the last day of trials (different schools do their trials at different times though), so consider the fact that your major work will be due around trials, you need to work on it continuously and send in drafts throughout the year to avoid having to cram studying + working on it in the same few weeks. don't let that deter you from it though, if you're good at english, it's a subject which can improve your atar as it's the highest scaling english subject.