Pre-lockdown the large majority of students using this app were game based. Often children would use the Discord app to have conversations, share tactics etc. with their friends whilst playing their online games. But curiously the popularity of Discord has increased massively post lockdown and the majority of people are using the app just for messaging purposes. The age requirement for Discord is 17+, although I can’t see why as it isn’t dissimilar to many other apps out there with similar functionality.
With this in mind it might be useful to read THIS article from Internet Matters which has advice and guidance, including privacy settings, filtering comments, blocking/reporting and more.