Hi Frank, welcome to PTalk.com
At 19, 1 spray of Ammo is more than sufficient to cover your needs as you already naturally produce -none at higher levels as compared to older men.
You would be taking a look at IH and IO and finishing off with some IShine.
You may want to read up on some stickies here;
https://pheromonetalk.com/t/an-introduction-to-mones-names-size-strength-use-effects-length-of/43003
https://pheromonetalk.com/t/how-do-i-qualify-for-a-25-gift-certificate/19934
Useful to help you get started 
You can just layer them, you do not need to wait for them to dry