How do Human Traits Work?

I’m a relatively new player to the DnD scene. I’m creating a human ranger and was puzzled at the logistics of human traits, and I can’t seem to find the answer anywhere, although I might just be bad at researching.

On dndbeyond, when looking at the human race, under “Human Traits” (https://www.dndbeyond.com/races/human#HumanTraits) it gives a list of Marks and Houses, such as Mark of Handling Human, followed by House Vadalis, then Mark of Making Human, followed by House Cannith, so on and so forth. And then at the end of the list is “Variant Human” With this context in mind I have 3 questions.

  1. Are these Marks and Houses Canon? As someone who has never really played I have no clue if these are used regularly.

  2. Do the Marks that precede the house listed relate to each other? e.g. is the Mark of Handling Human something given to you if you choose House Vadalis?

  3. If you choose Variant Human, I understand that you forfeit the +1 to all stats in favor of the LVL 1 feat and extra proficiency, on top of the +1 to two stats of your choice. But if I choose Variant (assuming Houses and Marks are canon,) does this forfeit my choice of a house? Or do I get to pick a house on top of picking variant as a trait?