That's odd. It works here.

For reference my favorite sorts are Subscribed+Scaled and All+Top Day.

Check whether the Hot/Top/new buttons work; and also really the NEXT button. Those green buttons haven't worked for a while. I'm not 'me too'-ing so much as hoping I can help you flesh out the problems you're seeing based on what I'm seeing.

To be clear, I'm not looking for much support. My set-up is old and usually everyone says "lol, buy a new XYZ"; so they agree on a solution and I agree they should get perspective once they leave their teens.

Am I the only one that gets this? I tried uploading a video but can’t seem to regardless of file size

I don't think you can upload a video to Lemmy directly. People usually upload to another site and then paste the link in the URL field.

Toggling between sections makes no difference

This shouldn't happen, I'll poke around and see if I can replicate it.

so many different sections of lemmy makes it difficult to know where to post

Quick overview if it helps:

• subscribed, local, all, moderator view are different feeds that will show posts from different collections of communities:

  • subscribed shows posts from communities you subscribe to
  • local shows posts from communities on the instance. This can be helpful for topic specific instances, and on our instance it will get you a lot of the Canadian content. The full list of communities on our instance are here: https://lemmy.ca/communities
  • all shows all content that the instance knows about
  • moderator view only shows posts from communities where you are a mod.

• hot, active, scaled, controversial etc. affects the order of the posts on the feed.

You can set defaults in your settings once you know what you like, I haven't changed mine in a long time now. I use subscribed with scaled, but I recommend trying out things to see what you prefer :)

When posting, you will be posting to a specific community. What I like to do is navigate to it in my address bar. It will follow this format:

lemmy.ca/c/COMMUNITY@example.com

For example

• the fediverse community on lemmy.world: lemmy.ca/c/fediverse@lemmy.world
• the Canada community on lemmy.ca: lemmy.ca/c/canada (or lemmy.ca/c/canada@lemmy.ca if you find it easier)

Toggling between subbed/local/all/mod view does nothing

and

I just found out posting this that I need to be subscribed to the lemmy.ca support / questions in order to post here.

I can't duplicate your subbed/Local/all view, and I can post here even though I am not subscribed.
Are you using the actual website, or one of the many unofficial apps?

I tried uploading a video but can’t seem to regardless of file size.

Lemmy doesn't host video, you'll need to upload it elsewhere and link to it.