Which one to be done First? To monetize with Admob or to publish to Google Play?

  admob, android, google-play

I recently build an Android app, monetized it with Admob and published to google play. I came to know two things.

  1. When monetizing with Admob, it asks: "Is your app live on one of the supported app stores?" (or something like this)
    Here I saw a warning like "Soon unpublished apps will not be supported. (These are not the exact words).
  2. When publishing the app Google Play Console asks: "Does your app contains ads?"

So if I want to monetize my app from the start, what should I do?
Should I monetize the updated version?
Can I change the option on Google Play Console "Contains ads" after an update?
I am not an expert in Admob and Console and need guidance from experts

Source: Android Questions