How do you connect a ceiling fan/light, to an existing ceiling light?

Yep, Scooter's right, sounds like someone's messed up the wiring in that house seriously. You'll be 100% better off just hiring someone who can trace the wires back to their source and figure out just what's going on. Then you can get the light connected properly, and safely.

You've chosen a very good time to stop and ask. Power off at fuse. Reds all together (not connected to new light in any way).

Two blacks to blue neutrals on light black-with-red to brown live on light. Earths together and to light if light has an earthing point. Power on and enjoy.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.