Should I use custom Usernames for the kids in my program?

Every program is different, but we recommend using a naming system that is unique to your students while protecting their anonymity on the site. "SchoolnameFirstname" is a good choice, as the kids can recognize their classmates, but it still protects their identity.
 

If you have a large group, this will help you as a coach as well. You'll be able to recognize your students by their Username, and even sort them alphabetically.