I'd like to remove the left column of the Barceloneta theme -- it's a Nav Tree that has no use, since Nav is also present a the top. I have copied the theme, but cannot for the life of me find a way to customize the columns in a way that removes the left column. Please help!
Scratch that -- I think I've found a way. I had removed the left portlet from the "page" that I built for the homepage, but it was inheriting the parent attributes. Clicking the "block" parent option seemed to do it.
If anyone has a better solution, please advise!
The easier way is create a custom theme. Have you read the https://training.plone.org/5/theming/ training? It is maybe very useful to your case.