I beg to differ! I spy more cables hiding in the carpet
If you have two pairs of cables, the thicker ones are for the brakes (thicker=stronger in this case)
So there will be some lengths of housing to match each pair, in two sizes to suit the cables.
The lengths of brake housing will be one short (front brake) and one long (rear brake). You can run the whole length to the rear or trim it as needed by your particular frame. Post more close up photos of the frame if you need help.
Then there are three lengths of gear cable outer on the left. Two to run from the shifters to the frame, then one short piece to run to the rear derailleur.
You'll need good cable cutters to trim anything. Trivial with good quality cutters- invest!
All of the other little pieces are important too, there should usually be a plastic or metal 'ferrule' at each end of any outer cable for protection. They come in different sizes of course for the two cable types.