Hello @DesertFlower
You should be able to choose multiple files when selecting the content to upload. After you click "choose file" try pressing shift or selecting multiple files at one time for upload. They should all load then at the same time and you can submit them at once. Here is the Canvas guide (look for the choose file part - the guide shows one but you can upload a few at once)
How do I upload a file or image to my ePortfolio p... - Instructure Community
If that doesn't work, we may need more specifics. Are you doing this in your Canvas account or Portfolios outside of Canvas? Are you uploading to a project or trying to change a profile picture, bio, or something else?