>>7535This site is an image forum. a very old form of social media very similar to 4chan. it is made up of different "boards" listed at the top of the screen (you are currently posting on the /canterlot/ board). Each board has a general topic category that is allowed there, and may have unique rules.
Once you've selected your desired board, you either make a new "thread" or make a post in an existing thread. as the name implies, an image forum or imageboard is designed to feature images with posts. Many of us here use that feature to post as an "avatar" or generally consistent fictional character. Originally this place was strictly themed after My Little Pony G4, but it's basically a free for all now.
This site also requires you to use a user handle, which you seem to have figured out (I get a pass because my name isn't the auto -generated "anonymous" and very few users think to do the trick I use)
videos aren't usually hosted here, and if they are, they tend to be very seldom, or in a dedicated one off thread that may disappear. Only so many threads can be hosted after all. That's part of the charm of this place. Everything is mostly new, because old stuff gets discarded.
Feel free to head over to /pony/ where most of the activity is. or just post here with more questions and one of the staff will probably answer soon.