The class 1 medical does go into greater detail than the class 2. However if you are a normal healthy 16 year old, who has not suffered any major health issues in the recent past, then it would be very unlikely that you would have a problem. To put your mind at rest you might want to check the requirements for the grant of a medical class 1 with CASA.
If there is something specific you are concerned about it would be no harm to speak with an ME beforehand.
Best of luck.