For those making the switch that care about privacy, you might find this useful.

Note said:The Private DNS feature uses DNS-over-TLS, so you can't just enter the regular IP address of the server, instead use the address: dns.adguard.com
If you decides to use any other DNS service, just remember to use their DNS-over-TLS address, not IP address.
Note said:For iOS users, give DNSCloak a try which serves the same function.

The best method is just to outright disable Google Play Services entirely, get rid of all Google apps and side-load alternatives such as K-9 Mail, Firefox, or Textra.
Google Play Services is the privacy killer--have you ever seen the permissions list and what it's capable of doing in the background? It's scary. Disabling it will net you a ton more battery out the gate. Performance also comes up quite a lot.
If you actually believe you'll achieve any measurable amount of privacy just using Private DNS or a VPN with Google still tracking your every move, you're only kidding yourselves.
I just wanted to make some simple recommendations. People who are looking at using Android free of Google will find better info at XDA Developers, where there are smarter people than me who can go deep into it. It's just too complicated for the regular person and can make the phone impractical to use.
A VPN is a Virtual Private Network. VPNs do help for both privacy and for security. But as the saying goes in the cybersecurity field goes, "There is no such things as 100% security". One of the most secure options is Proton Mail because it is not subject to the privacy laws of other countries and it also uses a high level of encryption to secure the data for the users who use their service. However, again, there is no such things as 100% security.