This all looks like a good beginner project to me and you should be able to source everything you need from our site.
I’d recommend starting with just the LED strip lights and getting that working, then tackle the addition of the MP3 player board later. We have a tutorial that covers getting NeoPixels (trade name for WS2812 LEDs) working with an Arduino you can find here:
The pin number in the code may need to change based on which Arduino board you use, but other than that the code should be pretty much ready to go.
There is a 470Ω resistor on the input data line of the NeoPixel. There is also a voltage divider made up of a 1kΩ and 680Ω resistor. The ratio of the values in the voltage divider is the most important part as that determines what voltage it outputs.
If you want to get your head around NeoPixels(WS2812) LEDs then Adafruits uberguide is fantastic!