you don't have to go all in at once, mate. you can start by getting most important things in your control: your browser and search engine.
if you like the interface of Google chrome and can't part away with it: use brave. else highly recommended to use Firefox.
if you just like Google search results, use startpage, else use duckduckgo or brave search.

these two things alone would make a meaningful difference.

then for neutering most of third party tracking: use a private DNS(I'd suggest nextdns). it's just a "add a URL and forget about it'. it'll stop the tracking significantly.

then you can continue by replacing other inconsequential stuff like Google notes(use Joplin), Google assistant(don't use any of this "smart" crap), Google fit(just exercise regularly. you don't need to micromanage it).

then next step would be to start making some tough decisions: replace the keylogger that is Google keyboard with it's open source equivalent heliboard.

then eventually you can go hardcore and use Facebook and other crap on browser only.

so, all in all, even if you do only the first two(or just first) step, you're already 50% there.

let me know in case you got any questions. and happy journey.