How Do I Move Google Photos to iCloud?
Export with Takeout, fix the dates and places, then import into Apple Photos with iCloud switched on.
Download your library with Google Takeout, then import the files into Apple Photos on a Mac with iCloud Photos turned on. They upload from there. Apple's own transfer service can move them directly, but it does not carry everything.
The step people skip is the middle one. Import a raw Takeout export and every photo lands on today's date with no location, because the real values are in .json files Apple never reads.
Fix them first. Takeout JSON Metadata Fixer writes the dates and places into the photos, converts HEIC if you want, and then the import builds a proper timeline. It runs on your own computer and is free for your first 500 photos.