To me, the first easy step is the email. There are good alternatives to Gmail, including (but not limited to) Migadu, Fastmail, ProtonMail. My opinion is that you should get your own domain (so that you can have an address like username@neuralkoi.com), because then your address can stay forever and you can switch provider in the back. Say you use ProtonMail behind your @neuralkoi.com address and decide to move to Migadu, you can keep the same address. Meaning that you don't have to tell everybody that you changed.
Regarding the Google Workspace, again there are alternatives, some self-hosted (but that's harder to do). One that comes to mind is the Proton suite.
Search engine is pretty easy to switch to (there is no network effect there). I really like Kagi, DuckDuckGo works well. For a non-US alternative (if you're into that) there is Qwant (Ecosia is European on the paper but I believe they use US servers).
For the mobile phone, you're pretty much screwed: it's Apple or Google. You can try to support projects that try to limit the power of Google over the OS. My personal favourite is GrapheneOS, but it only supports Pixel phones (hopefully that will change eventually). Linux on mobile is interesting, but IMO far behind AOSP (the open source part of Android).
