If you “find out” something, it is the same as saying to discover (knowledge). To “break in” is when someone enters a house or building illegally.
1. When did you find out that Santa Claus/ Father Christmas as we know him does not exist? Was it a shock?
2. When you travel to another country either on vacation or if you immigrate there, you will find out many new things that you never knew before - about the culture, language, customs etc. You will broaden your horizons (gain more experience in life).
3. When I found out that “Pluto” is not really a planet, I felt like I had been living a lie - because there are actually only 8 planets in our solar system, not 9 as we previously thought.