Where exactly are you supposed to put...
Where exactly are you supposed to put your hydration system? Is there a specific place or do you decide where to put it?
There should be a sleeve at the back of your pack (the part that's against your back) that you can slip a hydration bag into. Alternatively, you could check the outside and find the hydration port (where the hose is supposed to come out) and look on the inside near that site. The hydration sleeve should be close to it.