single page template

Hello,

I am creating a post template so I inserted a row and divided it in 2 colums 1 for post and 1 for sidebar.
my problem is that when i click on view on mobile, the “sidebar” is really thin .. how do i delete the sidebar for mobile or put it so that it’s displayed under the sidebar on mobile?

Also is there a single “post” title shortcut? the single “page” title isn’t using my H1 font that I entered in theme panel.

Is there any way to put “single post author” and “single post date” next to each other in the column that I created for the post? I Don’t want to start messing with more rows again, I have 1 row with 2 columns left = post right = sidebar –> I want to add the single post author and single post date next to each other in the left column.