Those guys that fly these P3 without GPS are great pilots.
No, we're just not stupid enough to try it in our house
Seriously, if you are not confident flying (outside) even in attitude mode, I would recommend you buy some cheap quadcopter to practice with. Could save you some money and its fun to do.
FWIW, what you call attitude mode or sometimes manual mode (cringe), is what I and most.. "real" pilots consider almost fully automatic mode: the phantom auto levels when you center the sticks, it automatically holds is bank and pitch angle and will never exceed certain limits, and the throttle is controlled automatically to maintain altitude. Even when yanking the control sticks.
My racing quads have none of those features. The throttle stick actually controls motor speed, not altitude (it also doesnt center). If I increase forward speed, I need to add more throttle or the quad will lose altitude, and vice versa. The other sticks control rotation rate, not bank or roll angle. So if I center my sticks, nothing happens, the quad maintains whatever orientation it was in. Upside down, sideways, whatever. To get it level, I need to actively steer it to level.
Anyway, you may not want to learn that, but flying a phantom or any other quad in self leveling "attitude mode", you really should master and have no problems with whatsoever.
edit: none of that makes me great. I just sometimes manage to not crash
. Great pilots can do this: