It helped me tremendously in college, and I still use it today, both for past knowledge retention, as well as learning some new things. It is an incredible tool.
As far as the learning curve goes, I would recommend this: just use it as is. You can dive down a rabbit hole of optimizing your learning approach and adding the right extensions, but that time is better spent just studying what you want to learn.
Use the Cloze format, keep cards limited to a couple sentences at most, and practice daily for a couple minutes, and you can’t go wrong.
I ran into the same issue you did. No verification email, and my login credentials won’t work on the app or on the website.