You might be able to get your list of servers from Discord Data request. Go into your user settings, privacy and safety, and scroll all the way down. There is a button to request your Discord Data. I do not think there is any other method to get the list of servers you’ve been a member of aside from this.
The easiest way to report someone on Discord is to simply tell a moderator of the server that the inappropriate behavior occurred in. If you want to report something to Discord’s own Trust & Safety team, you’ll need to turn on the app’s Developer Mode.