Too many spacers in between! How to remove?

Hi there.
I have a few pages that either have spaces right under the menu before the full width picture, or they have big wide spaces in between sections.

Now–I do know html, but I cannot for the life of me find out how to remove these spaces and make things sit flush up next to each other without these. I have searched the code and tried many things, wasting a lot of time. Can you tell me why spaces would appear and what the code would look like and how to remove them?

Also, where do I modify the TOP BAR? Can’t find it.

Also, suggestion, please put a narrator on your training videos. Music just doesn’t cut it.
Thanks,
Shawn Dady