Why is this site making students/teacher sign in to access most of the courses? Do they not understand 1st graders can’t remember their address let alone a password? This is what happens when non-profits get too big; it becomes more about their own power and bureaucracy than the original mission. Please fix this! Why would you make it harder for people to use? You’re supposed to help kids!
I’m sorry you are experiencing the frustrations as well. Many of the activities don’t require a login at all. You may want to look at this page and filter it for activities that are age appropriate for your students, you can find a number of activities that don’t require logins.
Use computer science to explore and learn about AI!
Also, many of the course based activities also don’t require logins, but any progress students make isn’t saved.
There are distinct advantages of using logins, the main one being that progress can be saved and students can work from more than one different computer, but I agree with @edavis that the picture login works great. I used it with my middle school students for years, even though they are old enough for the other logins, for that same reason, that they could remember it.
I hope one of these solutions will work for you and your students!