Newcomers' tutorials are presented as webinars in advance of each IETF meeting as well as the Sunday before every in-person IETF meeting. When possible, versions are provided in the local language where the meeting is taking place. Here is a recording from a recent IETF meeting.
Scott Bradner, who revised and presented this tutorial at the IETF for many years, produced a series of bite-sized IETF introductory videos specifically designed for online viewing for his Harvard University Extension School class. The Harvard Extension School graciously agreed to close caption the videos and let the IETF make them available for general viewing. The playlist of these Newcomers Training videos can be found here on the IETF YouTube channel. A more complete list of Tutorials can be found on the IETF Datatracker.