Advanced Cocktailcrafting is a Disco Bandit skill, so it's not available to you as a Turtle Tamer. It is anyway one of the most useful skills you can find in the game, giving you access to some of the best quality cocktails easily available.
If you've started Ascending to perm some skills, consider doing a Disco Bandit run just to get Advanced Cocktailcrafting, it will help you greatly in subsequent runs (especially in Hardcore), getting you much needed adventures and stats; just remember that Coconut Shells let you create Muscle cocktails, Paper Umbrellas are for Misticality cocktails and the Ice Cubes are for Moxie.
The only other use for your cocktail garnishes is as equipment, but if you've just reincarnated you'll surely find better weapons and armors in a few adventures, while later, at higher levels, you'll definitely have better equipment available.