I am confused here of whether I should describe each and every character with detail for readers to understand that character's norms, habits, beliefs and nature?
Do not do that.
All that matters is the feelings and reactions of your protagonist in the moment. Treat your reader like a ghost friend of your protagonist. If she recognizes fifty people in the hallway, she is not mentally or verbally going to go through a laundry list of characteristics and histories of everybody. You have two seconds for her to have a thought; that is all the reader gets too.
Talking about these norms, habits, beliefs and nature, or physical descriptions, are all a boring shortcut beginning authors try to take, and it doesn't work very well. You are basically asking the reader to memorize a list of features for a character and remember them for later, so you don't have to explain that X says "cool" every other word.
Instead, adopt the idea of immersion. Your protagonist is taking a certain path through the story, having encounters with people (perhaps with animals like pets) and with the setting. Show us his thoughts and emotions as they happen, including if he likes or dislikes somebody, fears somebody, is deferential to authority figures or not, etc. If people have quirks, he reacts to them as he does. Do not give the reader any "extra" knowledge besides that, it should not ever be necessary.
By analogy, think of a movie, opening on the crowded hallway of a school before classes start. We (the audience) are immersed. We get no special tags or asides or anything else; we see kids in action and hear dialogue, we see facial expressions, laughter, anger and we figure it out. The camera focuses on certain kids.
Joe just tripped Kyle and made him drop his books, Kyle only shakes
his head in resignation and kneels to pick them up. Joe walks away as
if nothing happened, except for his stupid smirk.
Pria is, as always, looking in her mirror. Who can blame her, who
wouldn't fall in love with that face?
Do I have to describe these three characters any further? As an author, your ability to show thoughts and feelings of your protagonist is what is important; the reader identifies with the protagonist and sees the world through his eyes and thoughts. Exactly what Pria looks like should not be told, because different readers have different standards of beauty and a specific description can actually alienate them. What matters is how the protagonist feels about her, and those are feelings the reader is willing to share; let them come up with their own mental image of a Pria they can understand feeling about in the same way.
I only describe character elements that will have some direct impact on the story, sooner or later. The later the better, except in the case of highly unusual or improbable characteristics (special talent or physical attributes) which should be described as early as possible, so they will be taken as "givens" instead of deus ex machinas.
For example, if your protagonist's best friend is the tallest person in the school, presumably that unusual characteristic plays into the plot somehow: They can reach what others cannot, they are on the basketball team and that matters, etc. Or suppose the friend is a chemistry wizard, or chess champion, or judo black belt, because that will matter.
Bring up unusual or outlier characteristics as early as possible, again without telling but showing. "Showing" does not have to mean a scene of chess or judo; it can be as little as an excuse in dialogue: "Not tonight, it's chess club! The district tournament is just a month away." A line like that could set up the protagonist, in a month, to accompany his friend to the tournament in some other town, as part of the plot, without seeming contrived (as it would if this chess tournament suddenly appeared three pages before the trip and too-conveniently solved the protagonist's problem of getting to this other town).