Public schools (tax funded) are broken into three levels: elementary, junior/middle, and high schools.
Kindergarden, ages 5-6, is not required in all school districts. So, some children begin school in kindergarden, and others begin in Grade 1.
Primary school, for the most part, holds grades 1-6 in the same building, is composed of classes of up to about 30 kids, with one teacher covering all academic subjects. Some schools have specialty teachers for certain subjects like gym and art and music, so they may have a different teacher for those subjects. In some school districts, grade 6 is in a separate building (usually due to overcrowding issues). Children participate in primarily team sports, but there is not usually competition between classes.
Junior high, or middle school, is generally grades 7-9, although in some districts it can be grades 6-8, or only grades 7 and 8. This is when students start going to a different room for each class, with a different teacher for each subject. Students may begin participating in competitive sports, although not as extensively as in high school.
High school is grades 9-12. These are the grades that are included when colleges evaluate applicants for admission... even though sometimes grade 9 is housed at the junior high/middle school Competitive sports such as track, bowling, cheerleading, basketball, softball/baseball and football can be quite extensive, and students who excel can earn sports-oriented scholarships, as well as (or instead of) academic scholarships.
I can't tell you whether it is like Netfix or not, because I am not familiar with what you are watching on Netflix. However, any program or book will present the one scenario that pertains to the situation being portrayed. Broaden your exposure; don't rely on only one source of information.
We also have private schools in the US, for which parents must pay if their children are to attend. Some of these schools have ALL grades in one building. Some of them are religiously-oriented, and some of them can be boarding schools, and are VERY expensive.
Finally, in the US, we also have "home-schooling". In the US, it is THE PARENTS who are responsible for educating their children, whether they choose for their children to attend public, or private school -- and some keep their children at home and educate the children themselves. Sometimes, parents of "home-schooled" children band together and may teach children from several families out of someone's home. Some parents of home-schooled children don't actually teach them, but instead pay for online programs, and their children are educated primarily by taking computer classes. And, yes, there are some parents who keep their children home and SAY they are teaching them, but really teach them nothing. Thankfully, this doesn't happen often, and if discovered, these parents can get into a lot of trouble.