I made the move a year or two ago (time flies) and couldn't be happier. I have a throwaway gmail account that I setup using a temporary number for verification. Just make sure you setup 2FA immediately after setup so you don't need to use that number again. If I recall correctly, Google pushes the Google Authenticator app and doesn't tell you that you can use any other 2FA app for this, but you can.
I use Bitwarden to manage my passwords and 2FA/TOTP. Credentials are stored online (encrypted of course), so if you want to use something local on an app that doesn't need network access, I've heard KeePass is the one to use. I haven't personally used it. Aegis is very popular for offline 2FA. In fact, I don't think there's a need for 2FA apps to have network access at all.
For payments, consider a service like privacy.com. I have the free account and it's served me well. You have to go through KYC verification and/or link a bank account, but the cards you generate are throwaway and you can use totally fictitious names and addresses when providing your billing details to merchants. This ensures merchants know nothing about you (including Google Play Store) even if privacy.com and your bank know exactly who you are. Recently my wife had her debit card number compromised. Had she used privacy.com and locked a single use throwaway card to a single merchant, it never would have happened. In my mind, that's an often not talked about benefit of privacy.com.
As for those apps that require Google Play Services to run your business...use a secondary profile for those. Profiles have their own encrypted data and apps can't interact across profiles.
Also consider using webapps where possible to avoid downloading privacy invasive applications. You'd be very surprised at how many apps have websites that are pretty robust and eliminate the need for having an app on your phone.
Do your research. This community gets a bad rep for some reason. Everyone here and in the Matrix rooms have been extremely helpful. This is a great community of privacy conscious folks that are willing to help others mitigate threats according to their models.
Cheers!