Hey 👋
Photos should also appear in the files app so you should be able to access them from there, you can also access them by going to Settings > Storage > Images. Can you confirm that you are able to see images in those locations? I don’t believe photos should be saving to just Google Photos, at least not by default or unless you’re using Google Photos to remove already backed up media.
As for alternative gallery apps i dont have any recommendations myself but there are options out there, Gallery is one i see mentioned often.