The mainstream view is that Acts is a completely fictional novel.
See Richard Pervo, The Mystery of Acts (Santa Rosa, CA: Polebridge, 2008); and Richard Pervo, Acts: A Commentary (Minneapolis, MN: Fortress Press, 2009), for the most thorough accounting of this fact (see especially the latter, pp. 17-18), with substantial support in Thomas Brodie, The Birthing of the New Testament: The Intertextual Development of the New Testament Writings (Sheffield: Sheffield Phoenix, 2004), esp. pp. 377-445 (on Acts specifically); Dennis MacDonald, Does the New Testament Imitate Homer? Four Cases from the Acts of the Apostles (New Haven, CT: Yale University Press, 2003); and John Dominic Crossan, The Power of Parable: How Fiction by Jesus Became Fiction about Jesus (New York: HarperOne, 2012), pp. 196-217. See also Clare Rothschild, Luke–Acts and the Rhetoric of History: An Investigation of Early Christian Historiography (Tübingen: Mohr Siebeck, 2004); Loveday Alexander, ‘Fact, Fiction and the Genre of Acts’, New Testament Studies 44 (1998), pp. 380-99; and P.E. Satterthwaite, ‘Acts against the Background of Classical Rhetoric’, in The Book of Acts in its Ancient Literary Setting (ed. Bruce Winter and Andrew Clarke; Grand Rapids, MI: William B. Eerdmans, 1993), pp. 337-80.
Dennis MacDonald points out the shipwrecks of Odysseus and Paul share nautical images and vocabulary, the appearance of a goddess or angel assuring safety, the riding of planks, the arrival of the hero on an island among hospitable strangers, the mistaking of the hero as a god, and the sending of him on his way. Paul’s resurrection of the fallen Eutychus is based on the fallen Elpenor. The visions of Cornelius and Peter are constructed from a similar narrative about Agamemnon. Paul’s farewell at Miletus is constructed from Hector’s farewell to Andromache. The lottery of Matthias is constructed from the lottery of Ajax. Peter’s escape from prison is constructed from Priam’s escape from Achilles.
Randel Helms has shown that other elements are borrowed from the Book of Ezekiel: both Peter and Ezekiel see the heavens open (Acts 10.11; Ezek. 1.1); both are commanded to eat something in their vision (Acts 10.13; Ezek. 2.9); both twice respond to God, ‘By no means, Lord! (using the exact same Greek phrase, mēdamōs Kurie: Acts 10.14 and 11.8; Ezek. 4.14 and 20.49); both are asked to eat unclean food, and both protest that they have never eaten anything unclean before (Acts 10.14; Ezek. 4.14).
Acts contradicts Paul's own autobiography in this letters.
For example, we know Paul ‘was unknown by face to the churches of Judea’ until many years after his conversion (as he explains in Gal. 1.22-23), and after his conversion he went away to Arabia before returning to Damascus, and he didn’t go to Jerusalem for at least three years (as he explains in Gal. 1.15-18).
In contrast, Acts 7–9 has him known to and interacting with the Jerusalem church continuously from the beginning, even before his conversion, and instead of going to Arabia immediately after his conversion, in Acts he goes immediately to Damascus and then back to Jerusalem just a few weeks later, and never spends a moment in Arabia.