It all depends on the length and focus of the story. If you want to write something short and fluffy, worldbuilding is not necessary and quickly intoducing each place the mc is visiting will be enough. I mean that, for example, if you have a scene in mc's home, you don't need to say where it is or what's in other parts of it before it's actually relevant to the story, or not even that. In lighthearted stories you can easily get away with writing that one character visited the mc without any details where each live and who they are, because what matters are the events happening when they visit each other.
Though if you want something with wider plot, I think there are two options:
1. Describing each place the mc is in progressively and going to wider perscpective with time. If the first scene is in home, first say where the mc is without anything more, when he goes out you describe where he lives, then when he comes to school you can introduce the political situation and the country by portraying various people in the school (assuming that's relevant). Then some time later the mc can go downtown and then you describe how the city is and where said downtown is witout the need to say it all alongside the description of mc's home.
You don't need any specific details though, unless it's in some way relevant to the story. I once wrote somewhere on similar topic, and I'm going to repeat that: don't write details that are not important to the mc, or even worse details he wouldn't notice. You can include some general facts, like that this is the most popular pub in the city, but that's because the mc goes there and he actually has it in the back of his mind each time he sees it. But there's no point in ranting about the state of the whole city with a number of specific details about it that only a specialist would know, because nobody cares.
Referencing what I wrote above, you shouldn't introduce things the mc doesn't even think about. It's just weird when you've the mc freshening himself up in the bathroom, you write how he goes down for breakfast and afterwards he goes out, and suddenly you give the readers a detailed description of where he lives. Saying he has a five minute walk to school and he lives in the better district of the city will be enough until something comes up that warrants a more detailed description.
2. The second option, keeping in mind what I wrote above, is to put it into dialogues. For example, some random character can say there's a new transfer student, and then you can smoothly shift the talk to 'remind' some character where the mc lives, what he likes, who he likes, all in relation to the transfer student.
Also, it doesn't need to be detailed, because readers can guess a lot things by themselves without you writing a paragraph about them. It breaks the immersion when the mc is in the middle of going to school and he starts describing everything around him like a tour guide. Get him a friend instead, who will point out some most important things in a small talk, bring up some rumors, ask about future plans, all which will give subtle hints about the world.
*takes a deep breath* Damn, that got kinda long. I can't call myslef an experienced writer, so take it all with a grain of salt, but I sure hope it helps.
PS: Also, to put things short, keep the details at the level on which they matter to the story. Some people might appreciate detailed worldbuilding, but if the whole story takes place in one city, then, in fact, you don't even need the name of the country. If you have some unimportant character whose only role is to help the mc find their way list in the city, you don't even need to say what's their gender. Likewise, don't write five paragraphs about a classmate. One will be enough, and the rest will come out in the interaction between them - if they develop into love interests, then you can write a rant in form of mc's thoughts somewhere later on.