The easiest way to find what CPU architecture your device has is by installing an app called Inware.
Click here to be taken to Inware on Google Play.
Install Inware as you normally would by tapping "Install."
Once you have Inware installed, click the "Hardware" button as shown below:
Then look under "Supported ABIs" and find an APK that matches what displays for you. (e.g. arm-64 v8-a) Downloading an APK that doesn't match will NOT work on your device.