I'm a 16 year old traveling for the first time and completely clueless...?

I haven't even traveled out of my state, but this summer I will be leaving abroad to Germany and will be staying with a friend. I am sixteen years old and am feeling a bit confused about the process to get this done.

I've been recently told about needing a notary (whatever that is) and having to specify my reason for travel (pleasure, business, etc) and needing my parent(s) to attend a meeting with a notary to keep them completely informed about every minor detail?

Up until a tiny bit ago, all I thought I needed was a passport, and parental consent to travel alone since I am a minor. What is all this talk about notaries?