How to properly construct objects on ATmega2056?

I was wondering the correct method to construct objects for use in the setup and loop scopes. I tried working constructing in the global scope, but I get garbage values printed to serial (probably from misusing pointers)? If I use the new keyword, then it works, but I heard that that is not best practice.

I is there a better way I should do this?

// navigator.cpp

#include "navigator.h"

Navigator::begin(Waypoint* w, int count) {
  waypoints = w; 
  pointCount = count;
  next = 0;                               // start with first waypoint
  course = 90;                          // Notice that initial course is due East

  Serial.println('here');
}

-

// navigator.h 

#define _navigator_h

#if defined(ARDUINO) && ARDUINO >= 100
  #include "Arduino.h"
#else
  #include "WProgram.h"
#endif

struct Waypoint {
  double lat, lon;
};

class Navigator {
public:
  begin(Waypoint* w, int);
};

#endif

-

// TransAt.ino

#include "navigator.h"

Waypoint w = { 43.36, -75.1 };  // These objects must be accessible in both setup() and loop(), but we can't use the new keyword
Navigator nav();                    // That means we have to do a lot of the heavy lifting here


uint32_t timer = millis();

void setup() {
  nav.begin(&w, 1); 
}

void loop() 
{ 

}