Microsoft provides very good on-line training for its Office 2003 and Office 2007 products. Here’s the link: https://support.office.com/en-US/article/Office-Training-Center-b8f02f81-ec85-4493-a39b-4c48e6bc4bfb I’m impressed with the quality of these lessons.
You may have already discovered that people who have Microsoft Office 2003 or earlier versions can’t open files from Microsoft Office 2007.
Version compatibility tip
If you’re an Office 2007 user who will be sending Microsoft Office files to other people, you can avert problems by saving your file as a "Word 97-2003 document." You can find the option in the "Save as type" drop-down box in the "Save As" window. Choosing this option means that anyone (who has earlier versions of Microsoft Office or Open Office) to whom you send the document will be able to open it.