1. By positioning your cursor at the appropriate place and pressing the F1 key 2. By using the Insert/Section Break 3. By positioning your cursor at the appropriate place and pressing Ctrl+Enter 4. By changing the font size of your document
If you are trying to force a page break in MicrosoftWord you will want to use the insert/section break and position your cursor at the appropriate place and press Ctrl+Enter. If you are able to familiarize yourself Microsoft Word to a point in which you feel comfortable with exploring and finding out all the things that you can do with it then this can be really helpful when using the word program to its maximum potential.
There are lots of ways to explore Word and learn about it from others as well. As always practice makes perfect and sometimes certain things have to be practiced multiple times before they are completely mastered.