After the comma it should read "you risk making _____ real." The ______ being what "it" refers to.

The first part is correct, but the second isn't. If you're trying to say that wishes that come true aren't always as good as expected there's a better phrase in English. It's "be careful what you wish for, it just might come true." The way it was written though I could see you going two completely different ways in what you were trying to say. (What you wrote after the comma is both grammatically incorrect and a strange use of the word "risk".)

1) ...making it real. 2) get the risk is a little awkward. Just 'risk', or more commonly 'run the risk'. 3) There is a problem of agreement of subject. What does your 'it' refer to? You probably should explicitly say what 'it' is. 'You run the risk of making your aspiration real'. Or perhaps better would be 'You run the risk of realising your dream/aspiration/...'.

The first part sounds fine but I would say /you run the risk of making it real/