You must tell the truth about happened on your college applications, but you have choices about what parts of the truth you emphasize. If, looking back, you think that you committed errors of judgment that you will be careful never to repeat, then that’s the part of the story to emphasize, NOT the technical details of the misunderstanding.
Yes, what @Hanna said! It was an error of judgment to even pretend to cheat. You were young, you have learned, you will never jeopardize your integrity again! It’s not our failings, but how we learn from our failings.
Even if your “random sentences” did not answer the questions on the test they may have alluded to topics that were on the test. Writing anything about the test can be considered cheating. If you write “the character was stupid” and a question on the test had to do with the character you gave information about the content of the test. Maybe you see this as pretending to cheat and not really cheating but any conversation dealing with the content of the test is inappropriate. Apologize for your bad judgement and stay out of any more trouble.