Put the kibosh on Autofill with Google
If you save things like credit card data on your Android device, that data ends up stored in your main Google account. You see what data you have stored in your Google account, and delete it if you wish. On a new phone, do not turn it on. If you are already using it:
Go to the Privacy settings, and tap Autofill with Google. (On some phones this is under Privacy -> Advanced settings)
Tap each of the options to see what data Google has stored under it. You will need to look around a bit in each area to find out how to edit or delete the data that Google has.
Use a better way to keep all the personal information you want stored securely online where you can easily access it but no one else (including Google) has access to it.