Hi Joe - Welcome to Pherotalk. 
Ammo is about as good a first choice as you can make. Its a well balanced mix of the three main pheros that will give you a good all-round social/sexual impression, well suited to your age range plus a bit of a confidence boost.
You will need to test to see what your effective dose is - all the basic info is gathered on this thread:
You may also want to think about the Socials Instant Shine and IO:
IS - is a happy/feelgood phero
IO - promotes smooth conversation
Both work very well with Ammo. In fact Ammo/IS is considered a classic social/attractive/happy mix by many here.