How likely am I to get the navy scholarship?

I have a 2030 SAT score, and a 3.7 GPA. I’m not in varsity sports but I’m in JV.
Also, how does the college program work? Do you guaranteed a spot?

No, there aren’t guarantees.

What is your major?

physics

Are you talking about ROTC scholarships? http://www.nrotc.navy.mil/scholarships.aspx