To see what style a paragraph is in just click on the paragraph and the name will be in the style name area. Word takes styles a step further. It assumes that some style names, such as heading , have special meanings. Word can then scan your document and look for any paragraphs with a Heading style. Thus, you should just type the text, and then assign a style name to each paragraph.
Word makes it easy bye apply a name Normal to all text paragraphs.
The document template makes it easier by defining the format for all the types of paragraphs you will use in a thesis. All you have to do is write your thesis, and apply the appropriate style name to each paragraph. Do not try to force formatting by adding spaces and blank lines. It will save you a lot of time when you need it most. For more on styles and document templates you should see one of the many books on Microsoft Word.