1 hour ago, g0dafk said:

There is so much auto generated code and it is so different from what i'm used to ( for 4 years i have only programmed in console, i'm a student, by the way ).

Sounds like auto generated code gets in your way and is just distracting. I don't know C++ Builder, but likely the code comes from windows, buttons, forms etc. that you edit with a extra GUI tool.

One option here is to make your own UI, eventually using the same graphics system that the game uses. For games this is the common way anyways. And even for tools we often do this (e.g. using a small library like ImGui). This way your code is also more portable between OS and IDE.

So for now i would ignore the confusion here, start with the game itself and decide this later. (Personally i have stopped using OS GUI elements pretty early and i do not miss that stuff.)

1 hour ago, g0dafk said:

Where should i start with the graphics? What should blocks be made of? What should the game "stage" be made of?

For the graphics there are two main options: 2D bitmaps (which you can blit to the screen using OS functions), or a 3D rendering API like OpenGL or DirectX (the way to go for games - but not necessary for Tetris).

There are many libs that make the latter easy. I remember SFML (graphics, networking and sound. I wrote a game in only one file using this), others are Allegro, SDL, .... (some are lightweight and initialize just a graphics window and give you the context.)

You can also do it without such a library, which is a bit more boring work to set things up.

Then you learn for example how to draw a colored triangle, and you draw one quad of a tetris block using two triangles. (again, using library makes this a lot easier. SFML would do very well here. You can draw sprites without learning how to texture triangles.)

For the stage you can use strings (allows to 'edit' small levels within code) but i would use a 2D array of integer numbers like this:

int stage[12][24];

For a block you could use:

int blockShape[4][4] = {

0,0,0,0,

0,0,0,0,

0,1,0,0,

1,1,1,0

};

So you can still 'edit' the shape of the blocks within code. (Under the hood 'string', 'matrix' or '2D array'... its all the same.)

You then can copy this block to the stage, move it on player input, scroll the stage downwards... all simple copy operations. You might need two versions of the stage, one with the static blocks, and another where the active block can be added to after movement for rendering and game logic.

I assume setting up libraries and learning their API is initially frustrating, but after taking that burden programming the game should be fun and Tetris is a very good choice.

I generate my classes by creating the files manually and adding them to the project. It's not necessary to use the IDE or any templates here.

It sounds like you're fighting C++ builder rather than the C++ language  or tetris itself.

The best place to find answers for C++ builder is in the C++ builder manual, or in a forum dedicated to that software.

This forum is about game development in general. While we know a lot about games (and the c++ language) in general. However there is much less knowledge about any particular software package, unless you accidentally bump into the right person. (Most people here use something else for editing code, so they just don't know the answer.)

Forums dedicated to your c++ builder package are filled to the top with people knowing about and using c++ builder, so you'll get better answers much faster.