Hello,
I've got an awful problem with finding any resources concerning this development board I acquired to start working with STMs.
(https://www.aliexpress.com/item/Hig...atibility-Multiple-Extension/32761236140.html )
Have you come across any useful materials that could help me get it started? I know ways how I can communicate with it and program it, but there are features mounted on it like: SD card and RTC which I would like to use. The problem is that I have absolutely no idea how these things are connected on the PCB...
It does not help that there is so little on the net about boards of this type (only offers...)

 

Chances are they cloned it from a real STM32F407 DISCOVERY board or NUCLEO.

To work with any MCU you need a programming platform. What toolset are you using?
In the toolset you will find libraries for using the standard peripherals such as SD card and RTC.

You can compare your board with the STM32F407 DISCOVERY documentation and see if they match.

If you are stuck, you can always restart your development using a genuine STM board.