Here are the official rules for getting bumped up a level. The default Discourse setting is that you can post a video link at Trust Level 1, but that can be changed by Steinberg and I’m not exactly sure if they changed it, but I have seen plenty of links to videos here so I don’t think they have :
Get to trust level 1 by…
*** Entering at least 5 topics**
*** Reading at least 30 posts**
*** Spend a total of 10 minutes reading posts**
By reading they just mean slowly scrolling by a post. This is set by the software (not Steinberg) to keep spammers out. It works pretty well.