Congratulations on a new bike:)
Brakes: The brake will need a bit of fine tuning- sometimes it is tight, but the wheels get locked up, so the mechanic can fine tune to your desires.
When 2 people are on a bike, the brake pedal is more higher, because of the load.
Engine oil: If you bought it from a authorized dealer, it has genuine engine oil in it. Replace according to manual/ dealer.
Always buy genuine oil from the dealer or a well known petrol pump. Even if normal shops do give discount, stay far away from them.
Regarding loose parts: Get them fixed or either replaced in warranty. A new bike shouldn't be like that.
My signals were not working after 3 weeks, got everything changed for free- The joy of a new bike:P
Drive carefully- it makes sure engine will last you long, and never neglect the oil change!!!