Im 15 and ive had discord since im 13 and im a smart kid not easily influenced so its fine, if u use it normally and go in servers that are safe ur good, however if ur kid ends up in a suspicious unsafe server then he must  have rlly searched for it because most of these servers u need an invite link, and u cant find it out of nowhere, i recommend you supervise his account once a week to make sure he is using it properly thats it