Everyone may reference slightly differently but this is how I did mine (been given a provisional A after marking).
So I'd write whatever in my text and then after what I wrote I would place a number in superscript. I'd then put the shorter citation in the footnote at the bottom of that page next to the correct number. E.g. the footnote would look something like (Donina et al., 2015 pp. 421-426).
At the end of the essay I then had a References list with all the references I used throughout my essay in full. This is not numbered but instead alphabetical order. E.g. The reference for a website would be like: Author/s, (Date), Page Name, [online], page numbers used, Available at: URL
After this I then had Bibliography which was all of my sources from the essay (all the sources in the reference list) AND any sources I looked at but didn't directly use in the text. Again this was alphabetical. To make the process quicker I used citethisforme to help make the references and would highly recommend it!
Hope I've helped and anymore questions just ask!