Build apk for google play

Hello, I have some questions about the digital certificate.

I generated the file nomeApp.keystore through cmd and through android studio the file nomeApp.jks, both told me to create a file pkcs12 that generates me other files nomeApp.keystore.old and nomeApp.jks.old.

Which of these certificates should I use to generate my apk, to put on Google Play?

I think the following guide might help you Android build guide