Front disc brake rattling noise
The rotor might not be perfectly true. Although the shop should fix it as it's a new bike, do be aware that big MTB rotors get out of true really easily and at some point you just need to live with it. This can be somewhat mitigated with two-piece rotors utilizing a beefier spider, but in the end you're riding trails; stuff breaks all the time. 

Is your thru axle tight? I know that with 9mm QR forks, violently turning and braking can sometimes be enough torque to momentarily twist the hub/dropout interface out of alignment, resulting in noise. A similar effect might manifest if your TA is not done up properly.