Things I want to ask my American friends

Here are a few things I don't understand and really want to ask my American friends about, but I'm afraid I'll sound dumb because I only know these things from TV sitcoms:

- Garbage disposals: what are they, does everyone really have them, how do you clean them, could they hurt you, why are they so terrifying, etc

- Wearing shoes indoors: for real? You actually do this? Sitting on your couch with shoes on? Do you have indoor shoes or just wear your outdoor shoes? What??? Why don't you like to be comfortable?

- What actually happens if you don't have health insurance and something happens and you don't have $40,000 in the bank to pay the bill?

- Is Thanksgiving a bigger deal than Christmas, or does it just really really seem that way?

- Does anyone actually try to fight the fact that your drinking age is 21? How is it that states are legalizing weed but you can't buy a case of beer until you're 21? I feel like people should care more about this.

- Freshman/sophomore/all the other ones: what? Why? Where did it come from? Why don't you just use numbers like the rest of us? I'm almost 34 and I still don't know what each of the words mean. While we're at it, why is everything just "college" when you have separate universities and colleges? Or...wait, do you not have separate universities or colleges, you just have universitycolleges? Are we Canadians wrong for separating the two? Maybe we are. Sorry no offence or anything.

- I just need to go back to garbage disposals for a second: like, do you put anything and everything down there? Does it mean that you all have like two sinks but only one can be used as an actual sink? Does it go to the sewer? Is it just another way of composting? I'm all for composting, but this seems intense. Have you ever had a garbage disposal injury? If it breaks, are there garbage disposal repair services, or is it just another branch of plumbing? When you were a kid did you have nightmares about garbage disposals coming to life and eating you?