One way is to look at reviews and ratings before choosing a book or other reading material. If it has warnings about inappropriate content, then stay away. Also, you can stick to well - known and respected publishers as they are more likely to have a screening process for content.
You can ask for recommendations from reliable sources like teachers, librarians, or friends who have similar reading tastes as you but avoid any content that might be considered improper. Another thing is to focus on specific genres that are known for their clean content, such as children's literature (even if you're an adult), certain types of non - fiction like biographies, or classic literature that has withstood the test of time.