When I reduce the page while viewing my website, the words don't stay put. They scoot around and no longer form sentences. Also nothing else, like an image, can go on the same line as one sentence because it will make the spacing as large as the image.
How do I fix this or work with it to stop it from happening? Can someone please point me in the right direction?

Browser: Mozilla Firefox

OS: Windows xp

Your page is adjusting correctly to fit the resized window.

Any idea what causes this? or how to fix it?

Browser: Mozilla Firefox

OS: Windows xp

There is nothing to fix, that is how web pages are supposed to work.

If you want to BREAK it you can set the layout to be fixed width but as you appear to have used a third party template you would need an understanding of css to find your way around the stylesheet.