So by doing this, the CC3D will know exactly what to do and I'll be good to go? 
No, actually not, its way more complicated than you think. You need some work before achieving position hold. GPS is accurate up to 2 meters and only helps other sensors. You really need everything calibrated properly before you start using it. Starting slow, getting the thing flying nicely in Complementary mode. Then you can step up and try Magnetometer which MUST be calibrated outdoors preferably using OPlink modem. Far from metallic objects. After that you can try INS31 sensor fusion (which is just Extended Kalman). Once you have good (not oscillating) signal in Atitude states in Scopes and rock stable model in the GCS, you can try flying with INS31, be sure it is rock stable in the air. Without the wind copter shouldn't drift much. After that if your magnetometer calibration is good, you can try GPS assist or position hold, but far away from buildings and people. And you should check before if your fail-safe is working (cutting off motors on turning off transmitter or lose of signal).
The reason not to fly close to people with GPS is obvious. As for the "far away from buildings" this is because buildings reflect GPS signal, and may fool your receiver with multi-path reflections into "thinking" the unit is few meters farer than it is in reality. Finally, these Ublox GPS modules, don't pull almanac from Wireless network and don't use WiFi for better precision. So its not like mobile phone. They usually have super-capacitor instead of battery (because capacitor does not get old though it only lasts up to 5-6hours). So before each flight you need to power the GPS, give it clear sky for 10-15min, let it collect stats and the you are ready to go, as it has up to date almanac for ~5-6h without being powered.