To create your HTML page you should use a marginless word processor, such as Notepad for Windows, or Simplepad for Mac. You should not use programs like MS Word or Corel's word processor, because they use margins and will mess up you page.
Begin by making a new folder for yourself to put all your files. Open your text editor and save it in your new folder as index.html (index.htm in Win 3.1). We name it index.html because in Geocities your home page is index.html (or index.htm).
Now you should have a blank document named index.html. Open your page by opening your new folder (not with your text editor) and open the web file named "index". Your web browser will open and you should get a blank screen, because you haven't writen anything.
In your text editor type "This is My First Web Page" and click Save. Then go back to your browser (you should still have the page in it) and hit Reload (Netscape) or Refresh (IE). You will see your first web page!
If you have closed your text editor and would like to edit your page more your can reopen your page in your text editor by clicking "Open" (in your text editor) opening the folder you created and in the "Open File" text box type index.html (or index.htm) and hit enter.