My MacAir didn't have an SD card slot-- I had thought that MacBooks had them. The one I still carry around in my camera bag cost $7 at Amazon. And my Z 8 also uses a CFexpress card (really fast!) so I carry adapters for that in in both my camera bag and in my computer bag.
I think you're going to have to look at the SD card with an adapter and see if anything is crazy about it-- it may be corrupted or damaged, but you can't know until you check. It may need to be reformatted, but you'd want to try getting the pictures off first!
If you haven't worked much with RAW data, you may need to look for editors that help with that. While I use Photos extensively to edit and organize jpg images, I don't think that it has much to offer for RAW files. I get both from the camera. Many of the jpgs are lovely on their own, but for the ones that seem like they could benefit from using their RAW information I edit them with either Nikon's NX studio (free!) or Adobe's Lightroom classic (subscription--bah!) I get the best results I can for these selected images with these RAW editors, and I save a jpg that I can import to Photos. I sometimes find that I can further improve the image some with Photos' own editor.
You can do a lot with RAW data to adjust for poor exposure, and Lightroom Classic is amazing at handling noise. But with bright light and proper exposure, the camera can produce great jpgs, and Photos can make reasonable adjustments with them.