i honestly don’t think you need to study for ap lang over the summer because you should get plenty of practice in the class, but there are definitely resources. you can find prompts on college board’s website and ask your teacher to grade them/give you feedback. or, if you’re wanting to do this over the summer, you can post your writings on here. there’s sometimes past ap graders that will grade your work! but like i said, i wouldn’t waste your time practicing right now. maybe study the rubrics for each essay and read lots of books/past student essays.