The school as a jungle is a metaphor. What is a jungle like? It is a place of danger, full of things that can hurt you, and you have to be strong to survive. The "law of the jungle" describes a state of affairs where the stronger, more powerful people are always right and the weaker ones suffer.
And yes, you can use "make it" in exactly the way you use it. It's a good idiomatic way of saying "succeed in travelling to": there's usually some difficulty involved (driving through traffic, catching a train).