Thanks for starting a topic in the forums! Note that I moved it to the Fundamentals forum. You should post a topic in the forum for the course you are asking a question about.
Parallel circuits: this is tricky for some folks to get, but if you keep trying, you will.
The thing that really helped me was the Zen trick that the Samurai shows in the second video in Unit 5.
Watch that video again – it’s only about 6 minutes – and see if you can put into your own words the difference between loads that are in series and loads that are in parallel, and the behavior of voltage and current in them.
I’m happy to go back and forth with you a little to nail it down, if needed.