A few questions to help with my characters

I have a few questions that will help with my characters.

1. I recently posted to purchase a power upgrade. But I'm unsure of how it would work. So what would I need to do?

2.I'm working on a new character, and I was wondering if there was a way that a demigod could be off camp almost always or if in camp for no one to know they were there? Also with being off camp where would they go. Because the person is pretty much a killer.

1) As far as I know, you tell an admin what power your upgrading and they'll say if its allowed or not.
2) Well if hes not going to Camp he can post in the off campus forums. This question was confusing, so if you could reword it a little please....?