I have the form that I need to fill out, but how do I get to them. Can I mail it in? And am I supposed to sign it or do I have to get an officer or something to do it?
The person who is applying for the pre-need determination needs to sign it- that would be you. And you can mail the form in, yes.
How do they decide who is eligible to be buried in a VA cemetery?
It is based on your service history as a Veteran, or the service history of the person who is sponsoring you, if you are a spouse, surviving spouse, or unmarried adult child.