Do I have to make a special study of the prescribed topic in the syllabus for Paper 2?

No, and it would be counterproductive to do so. Learners need no more knowledge of a prescribed topic for Paper 2 than they need for the same topic for Paper 1.

To teach the Paper 2 prescribed topic in more detail than other topics could mislead learners into thinking that Paper 2 is about detailed knowledge of the content, when it is primarily about interpreting, analysing, evaluating and using historical sources (although for this, learners do of course need some knowledge and understanding of the historical context, and the Paper 2 prescribed topic must still be covered).

To prepare learners for Paper 2 you should integrate source skills into the teaching and learning of the Paper 1 content. Giving learners regular opportunities to use historical sources during the whole course will enable them to gradually improve their source skills.