To use Word's built-in footnote/endnote tool:
If you'd like to see all of your footnotes (or endnotes) in one place, here's how to do it:
That will open a view of all your notes so you can easily edit, remove extra paragraph/return characters, and make paragraph or indent spacing changes. Just avoid trying to globally change font sizes here -- if you "Select All" and change the font size, that will change the font size for the note text AND the superscript number. Instead, remember that those two things are controlled by Styles -- Footnote Text (for the text) and Footnote Reference (for the footnote number). Modify those styles instead.
Microsoft Word has built-in tools for managing/formatting citations. They work fine for more modestly sized documents, but for a dissertation, it's likely that you'll need greater control and flexibility than Word provides.
We encourage you to take advantage of a dedicated citation/source management tool like EndNote, Zotero, or Mendeley. These citation management applications allow you to store your sources and easily insert properly-formatted citations into Word. They will automatically format both in-text citations and a bibliography.
You can learn more by visiting our Guide to Managing Citations with Zotero, Mendeley, and EndNote