I have a feeling that I at least need to give the idea that he's living in a mini-commune or whatever it's called when a multi-family dwelling has one shared kitchen.
Then say that he's living in a -- to him -- strange arrangement of however many different families living in the one building and sharing the kitchen, and show what he feels about it (eg confusion because he can't work out who they are and what they're doing there). It still doesn't mean you have to name them and their relationships all at once, and you certainly don't have to look up videos of people eating breakfasts in order to decide what they're talking about.
You seem always to be putting the cart before the horse. Your plot should be moving forward and your characters should be doing things. Concentrate on what's important instead of wasting time and energy on elements that go nowhere and add little or nothing to the story.
Maybe I should add more housemates and treat them as a noisy and chaotic hydra until one of them stands out enough to be named. I really don't want to go back and take another crack at MC being shown around; I'd rather just skip from becoming the apprentice to after he's been there for a bit.
I'd agree that unless and until these other characters actually do something that's important, it's better to leave them in the background. However, at some stage you'll have to accept that it's necessary to revise work that you've already written, because it doesn't gel or something needs to be added, and without that acceptance and the work involved in revision, you're unlikely to grow as a writer.
The Meet the Robinsons movie was probably breaking some sort of rule by having so many characters and actually trying to give us their names and relations.
It really doesn't help you by referring to other media for this or any other problem. Film, TV and graphic novels can get away with things that novels can't eg having lots of people on the scene, because our eyes can quickly take in the differences -- sex, colour of skin and hair, body shape, clothing, etc -- which the written word takes longer to convey. You have to work within the constraints of the medium.
Having said that, I really don't think it's of much use to you in referring to novels either, when it comes to what other authors have done in a scene and therefore why you should be able to do it. Analysing the scene might help, to see how and why it works, but there are likely to be too many differences in when the piece was written, the author's style and ability, even the author's fame and following (established authors can get away with junk at times, because their work will be bought regardless) to make the comparison meaningful.