Hi,
The good thing about the PUFF is that there are not that many components.
The bad thing is that transistors are going to be more difficult to find.
Most of us purchase from a store like Mouser, Digikey and others in the USA.
Das Musikding in Germany for example sells many parts and transistors.
Das Musikding is a good store because you will more than likely find everything you need with a single purchase saving you on shipping charges.
https://www.musikding.de/Startseite_1
It is important to get the right size parts like:
Resistors 1/4 watt
https://www.musikding.de/Metal-film-04W
Box Caps for uF values:
https://www.musikding.de/Polyester-boxed_1
Ceramic Caps for pF values
https://www.musikding.de/Ceramic-Capacitors
And Electrolytic Caps:
https://www.musikding.de/Electrolytic-Radial
Germanium transistors:
https://www.musikding.de/AC125-hFE100-110_1
You can learn a lot more by reading all of the guides on our Guides Page in your spare time.
You will have to purchase each value of what you need. That is what we all do unless you buy a kit. Sometimes if you know you are going to stay in the hobby it is better to buy part kits of resistors, capacitors and chips.
I hope that helps.