I too had a hard time with this puzzle. I don't remember exactly what I did, but I know the solution involved a walkthrough. Have you tried AppUnwrapper's walkthroughs? Most are both written AND accompanied by a video. I think on the whole she does a good job. She is iPhone/iPad based but in general the walkthroughs work with other platforms too.https://www.appunwrapper.com/2017/06/22/the-house-of-da-vinci-walkthrough-guide/
BTW, I liked House of Da Vinci and considered it worth playing, but I also found it a little buggy and hard to control at times. That said, wait until you get to House of Da Vinci 2...it's a treat to play.