You should revisit the module(s) that you have covered for English Advanced. While the specific text(s) that you have studied as part of a year 11 module(s) may not hold as much importance as those prescribed as part of the year 12 modules, it would be beneficial to remain familiar with all techniques, writing styles/features and/or analytical skills that you explored in term 1 and term 2. Once you have done this, getting ahead could involve familiarising yourself with the module(s) that you will study next term (if applicable) as well as familiarising yourself with the text(s) that you will study (if known), including themes/ideas/issues raised.
In terms of Mathematics Advanced and Mathematics Extension 1, you should revisit the topics that you have previously covered while prioritising important concepts and ensuring that you are able to effectively apply your knowledge, which can be done by completing practice textbook exercises in addition to past exam paper questions. If you feel that you are not fully confident about any particular aspect of the content, you should seek further explanations from your teacher. A quicker option to receive assistance may also be to post any maths-related questions on BoS. Once you have revisited earlier topics, you may wish to consider having a look at upcoming topics, allowing you to gain an idea of relevant concepts that will be emphasised. In doing so, you could use your textbooks, watch explanatory videos and complete relevant practice material. Of course, you should also ask any questions that you might have to your teacher and/or post them on BoS.
Regarding French Continuers, you should avoid reducing your exposure to the French language during the next two weeks and instead ensure that you maintain your speaking, writing, listening and reading abilities by interacting with relevant material, such as French texts, songs, cartoons/TV shows and speaking questions, as well as assessing you writing ability by developing written pieces in French. It is important to do all of these given that the aforementioned four elements constitute the components of French Continuers exams in both year 11 and, more importantly, year 12. Si tu priorises ces éléments et que tu fais de ton mieux, tu auras une meilleure chance d'obtenir de très bons résultats.
I hope this helps!