Hi June,
If you look at the Q&A attached to the relevant lessons, you will find some enlightenment but this topic is one of a trilogy we get most questions on.
So I can reassure you that you are not on your own. It has to become intuitive so can take a long time.
Take a look at this particular debate on just one example of Passé Composé vs Imparfait which you might find useful -
I hope this does not confuse you any further!