Column on left side of screen

This should be easy to resolve. Just tap the little “book” icon that’s currently highlighted blue:

Once the blue highlight is turned off, the left-pane will disappear:

You should note that this is a “sticky” setting. If you close the browser when the icon is highlighted, to browser will reopen with the left Favourites pane visible; by contrast, if the Safari window is closed whilst the icon is not highlighted, it will reopen with the Favourites pane hidden.

[Edited by Moderator]

What grey column - in which App?

Please attach a screenshot as it will likely help you to articulate your question.