Hello Sanaz;
All the module edit controls area accessible while logged in as Host
Log in as Host
Go to the page where Banners is installed
At top right hover over "Edit Page" and click the big blue button "Edit Page"
you'll see the page change with these icons appearing:
Hover over the "Pencil" icon in the center
Select "Banner Settings"
The 2nd and 3rd last settings are "Row Height" and "Column Width"
you can control these by numeric character input
You'll likely need to play with these to get your desired effect
To move the banner you click on the icon to the right of the gear setting and select "Left pane"
You can also drag n' drop the module from it's current position to a different position by setting the page to "View in Layout Mode"
Now you can drag the module to any other visible pane on the page
HTH