APA citations appear in text, within parentheses at the end of the phrase referring to the source. The reference list provides all the bibliographical information on the source, so the in-text citation only requires only the author's last name and the publication year. The page number is only given if a specific quotation or section of a source is referenced.
This is the sentence that I am citing (Smith, 2016).
This is the sentence that I am citing (Smith & Jones, 2016).
According to Smith, "we have much to learn on this topic" (2016, p. 10).