Almost universally a hobbyist would purchase the RP2040 mounted to a pcb with other i/o components (e.g. the Seeeduino Xiao https://wiki.seeedstudio.com/XIAO-RP2040/) There are other versions which bring out more lines to accessible solder points.

Of course you can design your own custom board, but I'd wager most people don't need or want to do this.