Optional, but recommended: Scramble PIN layout to protect against over the shoulder attacks. I.E. Someone watches you enter your pin, then follows you, steals your device and tries to unlock it.
Settings -> Security -> Turn on Scramble PIN Layout
Discussion
Go to settings and search for "Passwords & Accounts" set your system Password Manager here (I recommend Bitwarden, ProtonPass or KeepassDX)
Toggle off Google
Choose to use GrapheneOS or Google Camera. I prefer Google Camera.
Open Camera App -> settings -> Toggle off Save Location
Note: This will not save location exif data to your photos which is more secure and private, but you will not be able to search for photos by geographic location.
I highly recommend keeping this off, but some clients insist on using it, so another option is install ExifEraser and share your photos to it for processing and saving (in it's own storage scopes folder called something like, "ExifErased Media" for example) before sharing on the web.