You can quickly see which of your accounts is default by visiting the Google website and clicking on the profile icon in the top-right corner of the page. If one of the accounts doesn’t say “Default” next to it, you’re already using a default account. The first account you signed in to was a default account, so deleting that means logging out of all accounts.
This can be done by:
On google.com in the internet browser and click the profile located in the upper right corner.
After this, select “Sign Out All Accounts” from the pop-up menu.
If one has signed in to Google Chrome, a message will tell you that your account has been halted for syncing.
Click the “Continue” button to proceed.
Users can sign back in with an account that you want to be the default from now on. From the upper right corner of the Google homepage, click “Sign In.”
From all the accounts signed in with signed out, select the one you want to be the default one, or click “Use another account” to sign in with a new one.
You can check that this has changed correctly by opening a new tab and going to Google. The account icon will be the one you selected as the default, and there will be no changes to the pages that are already opened.