Question: I said or it came into my heart that Islam doesn't make sense but I didn't act toward it. Is this a kufr act? And while I was watching a TV show its was a Hindu show there it was about cleanliness the boy said that soon our city would world's most cleaned city but after awhile there came a monster who made it unclean so I said if Allah's doesn't will something it doesn't happen but it's a Hindu show so I said it not about Rabb so did I do a sin? Did I do kufr? How should I repent!??

Answer: 
If you did not act upon what you thought there is no sin on you. Ask Allah to guide you and seek information on Islam from authentic sources so that your doubts can be addressed. Be patient as the answer may not come right away.
Ibn Taymiyyah wrote: “Seeking forgiveness is from the greatest of the good deeds; and its door is extensive. So whoever senses a deficiency in his statement or his action or his circumstance or his sustenance or in the fluctuation of the heart; then upon him is Tawheed and seeking forgiveness. For in the both of them is a cure if they occur by way of truthfulness and sincerity.” (Majmu’ Fataawa 11/698)