This was a fun challenge! I thoroughly enjoyed the 'open-ended-ness' of it all, where we could use whatever frameworks and libraries we wanted. Thank you for that!
While I wanted to stick to your mock-ups as much as possible to show that I am able to do such, I do think that this UI/UX could be improved upon. For example, it would be a better UI/UX flow to have the "Cancel and Next/Submit" buttons loaded directly under the inputs -- as that would mean less traveling and/or looking to find the next steps.
Also, I chose to actually throw the User Group selections into a database and have it link up, thus making this a full stack assessment which is heavily geared towards front-end. :) As I intend to deploy this to Heroku, I wanted a cleaner and more easily expandable framework in place, rather than just a file of hard-coded options.
Lastly, I hope the little additions of password or email verification, snackbar alerts, responsive design, favIcon logo, and conditional rendering don't go unnoticed! :)
Hope you enjoy looking through my code, have a great day!
Best,
Ryan Maas