I've been running Immich for about 6 months now, and it's smooth and stable.

I've synced my camera roll to it and loving it.
Next step is to move the ~150gb of media on Google-Photos over.
How do I best do that?

I also have some other issues I'd like to address before or after the migration:

1. I have a bunch of crap mixed into my Google photos, old WhatsApp images from meme groups I used to be in etc.
2. Thousands of photos of Ex girlfriends mixed in (not exactly sure what to do about these)

Is there a way to siff through these efficiently and keep what I want? I have ~20k photos some dating back to 2006 so it feels like a mountain to climb.