I'm inferring you want to do this.
An easy way is simply to put <big> in front of your text. The more times you put it, the bigger your text will be. I used four above. And </big> to return to the default size.
Hope that helps. Feel free to inquire further.
What I was looking for was a way to increase the font size on the web-site when I browse. I thought I had seen that years ago, but can't find it now. The problem is that I am using Duck Duck Go, and Free Republic displays in a much smaller font than any other web-site I look at.
So, I opened Mozilla Fire Fox, opened the settings, and changed to font size to 110%. Problem solved. Now I use Mozilla for DR, and Duck Duck Go for everything else.