As a 16 year old do I have my first amendment rights and what are my rights when approached by an officer
As a minor, any rights you have flow through your parents or guardians.
If a police officer approaches you, I suggest you remain calm, and resist the idiotic temptation to start spouting off about any rights you THINK you might have.
Legally, all minors are considered "legal incompetents".
In other words, courts don't recognize you, insofar as rights are concerned, until you've reached the age of majority.
If for example, you were injured walking down the street by a falling debris off an tall building. Your parents would have to bring a lawsuit on your behalf, as you're incompetent to do so.
If you're approached by a police officer, and want to be a legal big shot, I suggest you remain calm, be cooperative, be polite, and say, "My name is Mike Minor. I was born on June 1st, 2000. I'm a minor and can't answer any other questions unless my mother or father are present. May I call them, or will you do it at the station house?"
Better advice is to obey all of THEIR laws, don't be a smart ass, and you won't have any trouble with law enforcement, ever.