Q. Where can I find a tutorial on APA style?
The University Libraries maintain this guide to citing in APA: http://libguides.murraystate.edu/citations/citations/apa
You can also try the Purdue Online Writing Lab (OWL). This is the link to their APA guide: https://owl.english.purdue.edu/owl/resource/560/01/
I also suggest you try this site from Easy Bib - http://content.easybib.com/citation-guides/. It's just a guide. To use EasyBib to manage APA citations, it's a $20 yearly fee.
Waterfield Library also has copies of the most recent styles guide, including APA. They can be used in the library only.