I'm actually in the slow process of this as well. Moving to DDG is the easiest starting point; in the beginning it's tempting to type g! with every search until you start trusting the results. Next I changed from my Pixel 2 to a SailfishX on a Sony phone. I'm planning on moving to Owncloud for contacts/storage/docs next. It's surprising how I've paid for Google to deeply invade my life.