Relax, you dont need to stress from now. Even for your options, pick what you enjoy. Your first year in gcse isnt gonna be as serious as your second year. My only ‘tip’ is that when next year starts, dont take everything in all at once. Dont start too early nor leave off everything last-minute. Theres a reason gcses are a two-year thing. Learn everything bit by bit and understand it fully.
But for now you really dont need to touch a book, youll be more than fine, just enjoy your summer.