I understand you can buy the components from Digikey but you have to print a PCB with those components, right?
So it's the PCB printer that should have access to the components, no?
Since the PCB is the board only, component information is actually not required to manufacture it. If you want a functioning device however you do have to source the components (e.g. from Digikey) and solder them to the PCB. I would recommend starting with an easier circuit (the electron-detector above might be a good candidate!) and ideally find someone to teach and help you (maybe at a local hackerspace? youtube tutorials might get you there if not?)
There's also this popular comic for teaching soldering to beginners that might help: https://mightyohm.com/blog/2011/04/soldering-is-easy-comic-b.... More links like this can be found on our list: https://github.com/kitspace/awesome-electronics/
The other option is to have a manufacturer solder it for you (e.g. Aisler and JLCPCB will do this for you), but if you have no experience building and debugging electronics I wouldn't recommend it (since it can get expensive and you can easily end up with a non-functioning device).