You will basically need to start fresh with a custom rom as google services are deeply ingrained into the standard operating system. Its almost impossible/not worth it even to to to get rid of those once they are installed. You could check first, which custom roms are available for your phone. Graphene, divestos and calyxos are probably the most private roms, but only available on a few models. Lineageos is widely available but will need extra steps to degoogle.

If a custom rom seems like too much hasle your can improve your privacy most easily by choosing a tracker and dns blocking doh/dns sever on android. It only takes minutes.

Android settings -> search for private dns -> chose private dns provider hostname -> doh.mullvad.net

More examples for providers here: https://www.kuketz-blog.de/empfehlungsecke/#dns