To view the contents of an APK file, you can use any archiver. A good example is 7-Zip, a free and open source archiver, which is available here: https://www.7-zip.org/download.html.
To unpack an APK file, right-click on it, choose 7-Zip, and then Open archive:
Contents of an APK file
Now you can browse the contents of the APK file and export its parts for further analysis. In the next section, we will focus on the Android manifest file: AndroidManifest.xml.