Welcome to the community!
There are lots of ways to handle video content in Discourse. In the topic composer, where a user would type in a new topic or reply to an existing topic, it is possible to upload video files. Most video files appear in a onebox which usually includes a nice preview image. There is also a livestream plugin which can be used in a stand alone topic or a Discourse Calendar and Events . There is even a Video stream plugin which supports RTMPS broadcasting!
Also the brand new Resenha plugin that allows you to add Discord style video and voice rooms to Discourse