images in portfolio gallery

I’m having a few issues with the portfolio:
1. I place the images in the portfolio in the order I want them to display in the gallery, however they do not follow this. I thought it displayed them in a random order, but I think they display in the order they are uploaded to the media library. How can I have them display in the order I place them in the portfolio?
2. If I delete images from a portfolio, they still display in the gallery even though they don’t show up in the post. I have to delete them from the library to get them to stop displaying.