In the screen shot below you will see that I want to put a space in between the text and the bold header but when I set it that way and hit preview it always goes back to having no space. A common Wordpress problem.

How can I fix this?

Go into the text mode of the edit box, (see arrow below)

Scroll around until you see the code I have circled below, this is the space code. Save this code someplace off your computer in say a notebook for future reference.