Hi @KimWheeler,
This is a seemingly easy question, but it can become complicated pretty quick. I'm going to make a few assumptions based on your question. I'm going to assume you're a teacher and that you can add a single person successfully in your course as shown in the How do I add users to a course? - Instructure Community - 1119 guide.. If both of these assumptions are correct, it's actually very easy to add multiple people to your course at one time. You can either separate the login/email info of each user with commas, or you can have one user per line (like copy/paste from excel would generate). I've added multiple people at one time with both of these methods, so they do work in general. If this doesn't work for you, could you please provide more info about your role, perhaps where you get stuck in the process, if you get an error message, etc...
-Chris
