Now that the System is successfully installed I would like to know how I can make it so every File I save and every Program I install will be automatically saved to the bigger Drive. This will be the first Time I've ever had 2 in one Computer
Programs you install? Under Windows 10? Not going to happen unless that bigger drive is also the system drive (i.e. "C:\" drive). Windows 10 will as default install all software on the system drive. There are some more or less unsupported options to work around that, but none I'd recommend - MS might decide to scrap that specific loophole on the next update.
As for user data, it's easy. Go to your user folders ("Dokumente", "Downloads", "Musik",...), do a right click onto each, go to Properties ("Eigenschaften"), select the "Path" ("Pfad") tab, then enter/select where this user folder should physically be located. Downside is that, especially with a German system, not every (english) software will work perfectly with this (I still need to figure out a) where ED stores my screenshots, b) where EDDiscovery expectes them and c) where EDDiscovery puts the .jpeg conversions...).
Also works across systems - various of my folders actually reside on a networked NAS.
With Windows 8, it's a bit more complicated (MS IIRC has a knowledge base article about this, keyword here is "symbolic link").