Google how to get original images from the Apple Photos app. That is the first thing you have to do as Apple places your original images in a Package file, which is really a folder, where the actual contents are hidden from the user.
Open Photos. If you have images that are already sorted in groups (e.g., events, travel locations, family, whatever. Select that group. Then go to File (menu)-> Export and then you have to make a decision:
If you export the photos (I have 4 selected so have something to show you), the top choice, any and all changes you made will be perminent, you can then import them into Lightroom.
If you select Unmodified Original, than the images will be exported without any of the changes you made. The advantage of this is that LRC can do a much better job of adjustments than Photos can but more importantly, as you get better with LRC, you will discover better ways to improve images. If you lock in your adjustments from Photos, some of those adjustments will no longer be availble to you because you do not have access to the original images.
Obviously the other disadvantage is that you will have to make your adjustments all over again.
FWIW, my choice is the latter.
Anyhow, after you've exported that block and imported them in LR, than you can start on the next block. Unfortunatley there is no real fast easy process for this. When you do your imports into LRC, please read up on things that you can do to speed the process up for Keywording, Presets and other features built into LRC. One good place to see/find this is at Lightroomqueen.com. If you register with her, you can access a free PDF that gives excellent basics on all flavors of Lightroom.