Learn to fly in ATTI mode. It never cease to amaze me how many people buy a Phantom and never learn to actually fly it (controlling it in GPS mode is not flying). If you don't want to risk your P3 when learning, buy a ~$30 toy drone and learn to fly with that one. Get used to what happens when the drone drifts, how different orientations require different inputs, how to stop a movement, how to recognize orientation, etc. That's the #1 piece of advice I always give people when they ask me what drone to buy: buy a toy drone and learn on that one first. Counter-intuitively, flying one of those toys is much harder than a P3, so you learn better and faster. Once you can control a toy drone, your P3 is so easy to control even in ATTI mode
Sooner or later your GPS and compass will have problems, it's inevitable. Knowing how to fly is the difference between safely landing your P3, vs hurting people and/or damaging property (or, at a minimum, destroying your P3). If I were DJI, I would stop GPS flying after a few flights and ask the user to learn about ATTI mode (connected to the account, so it doesn't happen with each new drone)
Over-reliance on automated flight is the reason why DJI drones had a bad reputation for fly-aways (the overwhelming majority were pilot errors)