The purpose of appendices is to provide material that would normally be distracting in the body of a text (e.g., a mathematical proof or the items of a scale that was developed).
If there is only a single appendix, it should be labeled "Appendix." If there are several appendices, label them Appendix A, Appendix B, and so on.
The appendices should appear at the very end of the paper, and each should start on a separate page.
There are two types of footnotes in an article, and each is handled slightly differently.
The author note is treated differently than a regular footnote. It is not numbered or referenced in the text. It is typed on a separate page, or if the paper is blind reviewed, it is typed on the bottom of the title page. The author note will include departmental affiliation if it has changed since the study was run, information on the funding source or purpose of the study (e.g., dissertation), and where someone can write for more information.
Footnotes are referenced in the text with sequential superscripted Arabic numerals (e.g., 1, 2, 3, etc). The notes themselves are included on a separate page at the end of the manuscript. Although footnotes can be valuable, it is best to avoid using them when their content can be worked into the text without disrupting the flow.