Thank you for your question!
The law of karma is basically how the Drama (the plot of humanity or the history of humanity) unfolds through every “actor,” every soul. The best way to view it is to imagine the story of how something beautiful transforms into something ugly (duality) Now, picture how every second of beauty changes little by little into that which is ugly. Every actor (soul) has that role “inside.” Every action has a repercussion whether we are aware of it or not.
“Energy” (spiritually speaking) is based on our thoughts and feelings. Even though they are not considered to be “actions,” in reality they have a consequence as well. There is a return to it.
If you have good feelings for a person, there will be a return felt on it. If you “fall in love” with a person; you may think that your energy is “good;” but it could be felt as “bad” by that person if there is no retribution, correspondence. However, love is a “good energy,” universally speaking but “falling in love “is not necessarily for it could be disturbing for another. That is why soul consciousness is important, because that energy is “good for all.”
As for your second question, the answer is yes. Your parents are there due to karmic accounts. The web of interactions have already been made in the roles of all the souls that you will be knowing in a lifetime. That is the wonder and beauty of this synchronization, or perfection in destiny.
Best wishes! 🙂