For example, I want to learn more about the campaigns function but I cant find any information or tutorials. Any help would be appreciated. Thank you.

The campaign is a means of grouping players, viewing characters in an adventure and sharing content. What specifically did you want help with?

I would love a video breakdown of how you use it to the fullest. Alas, I have spent a half day looking and found nothing.

I would suggest just messing around really; make a character with the builder, browse some monsters and spells, look through the basic rules, make a campaign and add the character you've made. It's not a super complex site, except for homebrew tools.