I don't know if you can get in trouble at first, but you can quite legally be asked to stop, and if you don't THEN you could get into serious trouble.
So, I'd say, unless your school promotes other religious after-school programs or clubs, don't do it. If your school DOES allow for the promotion of religious after-school programs or clubs, then you could try to start one for Pastafarians. Just be careful and err on the side of caution when it comes to trying to spread the word of His Noodliness in a public school.
(I assume you are a student, not a teacher, and are in a public school, not a college. If you're a teacher, you could loose your job over it. If you're in college, I doubt you'd run into much trouble.)
The Pirate Bard
If a man means me no offense and I am offended, I am a fool. If a man means me offense and I am offended, I am still a fool.
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"I am weary of chickens. How they look up at us with their small eyes as though we were unimportant." - Pablo Naruda
"Well they do. And we are. It's just hard to take it from a damn chicken!" - Greg Brown