Image: Inserting a footnote in google docs
To insert a footnote in google docs, go to Insert>footnote. Remember to insert it after the period of the sentence you're citing.
Use fewer quotes- quote important primary sources (first-hand accounts) or other works that you are deeply analyzing.
Citation generators are awesome (those in the search tools and those third party ones) but it's always a good idea to double-check what they give you- they are not always accurate!