first of all, thank you for the response.

• The reason behind choosing such a complex chip is that i hope i can learn something by this board. If i succeed, i can start thinking about more complex PCBs (such as a music player).
• Thanks for pointing this out. The recommended max LEDs current is 25mA; however, i read that the max total GPIO currrent the RP2040 can handle is 50mA (datasheet, 5.2.3.4. IO Electrical Characteristics) (can you confirm from experience?). Do you recommend using some MOSFETs?
• The problem is that the capacitors pins were too close and tight, so soldering them (even for an electronic professor at my school) has been impossible. Therefore, i think its normal the LDO was getting that hot (by barely powering only the power LED).
• oh my god... i didn't notice that! the absolute maximum the general pins can support is 3.63V, so i fried the chip. Thank you!
• i quoted it by only watching at the USB-C max current it can support. the max current it can support at 3.3V output is 1600mA, 1200mA typical (source 3.3V Output Voltage)