Should Endnotes Be in Alphabetical Order?

Absolutely. that is what Endnote does. If the rest of the references looks eactly as you want, then you can edit it, and change the bibliography (and citation, if you want) sort order to alphabetical. There are several choices there depending on whether you want the secondary sort to be Title or maybe year.

What order do endnotes go in?

Citation numbers should appear in sequential order. If using endnotes, numbered notes will appear on a separate, endnotes page at the end of your document and before the bibliography page.

Do your citations have to be in alphabetical order?

In APA your reference list always goes in alphabetical order occording to the first piece of information that's different. If you have multiple authors, then look at the first author for each work you are citing. ... If they have the same first and second author, then you'd go by the third author... and so on.