This is a microcontroller board based on the RP2040, compatible with (same chip as) the Raspberry Pi Pico.
Notable Features
The RP2040 can be used with Circuitpython, Micropython, or the Arduino IDE using a Pi Pico core
I recommend CircuitPython using the YD-RP2040 uf2 file, simply hold the BOOTSEL button, click the reset button, and release the BOOTSEL button, a drive will appear which you copy the uf2 file onto, once it’s copied the device will reboot automatically and a drive will appear called CIRCUITPY which is where you upload/save your python code.
I don’t personally know a whole lot about the capabilities of the RP2040, it’s the new young hotness where Arduino Nano and me are very much the old men, but there is a plethora of learning material on the internet.
A good place to start is the Raspberry Pi Pico Getting Started Guide just note that I found that my version of Thonnny has a bug which didn’t allow it to install firmware through Thonny, not a problem just download the firmware package and copy it onto the USB device which appears when you hold the BOOT button down and hit reset, the firmware will install onto the board and reset, then you are good to go.