You can get away with using bike cables for the brakes, for the starter clutch cable you will need a prefab one. Probably the Spartamet front and rear brake cables will fit your cycle, Treats has those in stock... probably all the rest of the trusted moped parts place have it in stock as well, so just as a example:
https://www.treatland.tv/SACHS-super-special-STARTER-DECOMP-cable-p/sachs-starter-decomp-cable.htm
https://www.treatland.tv/sachs-spartamet-FRONT-brake-cable-p/spartamet-brake-cable-front.htm
https://www.treatland.tv/sachs-spartamet-REAR-brake-cable-p/spartamet-brake-cable-rear.htm