Most ClubExpress layouts strictly enforce the width of your template. If you place content on a page or content box that is wider than what is allowed by the layout, it will be cut off. But you can also modify the width if you choose.
Navigate to the Control Panel > Website Tab > Setup > Look & Feel.
In the Site Editor Toolbar, click Width. When you select Width, the following panel is displayed at the top of your screen:
This panel provides sliders for each website element that can be dragged to make them wider or narrower. The website will adjust dynamically based on the position of the slider. Click Save to save the new width and close the panel, or Cancel to close without saving.
If your current layout has a left menu or just left content boxes, you will see a separate slider for the “column” in which these elements appear. If your current layout has right content boxes, you will see another slider on the right for the “column” in which these elements appear. The space in the middle is for the main content panel. Be sure not to make it too narrow since this is where your home page content, custom web pages, special function pages (calendar, forums, committees, etc.) and all admin pages appear.
In general, layouts with left and/or right columns may need to be wider than layouts without these columns, to allow enough room for the main content area in the middle.
You should also be cognizant of the overall width and how your website will display for members with smaller screens. Nowadays, almost everyone has a screen with at least 1024px across; many have 1280px, 1366px, 1440px or more of horizontal resolution. But if your member demographic skews older, they might have older and less capable computers, or they might have increased the zoom factor to allow for impaired vision. Another consideration is that not everyone runs their browser window fully maximized; they may be viewing websites in a window that is not using the full resolution of the screen.
You should size your website so that it fits within the screen for most people without needing to scroll horizontally. (Of course, vertical scrolling is not a problem; your pages can be as long as you need them to be.) Then adjust your content so that it fits within the defined width.