If its recent enough to change your order, can I suggest you email Mickaelia and get that Ammo changed to 1x - At 20, it is liable to be far too strong for you.
Once you have done your sweet spot testing and found you best doses, it might be ok to go up to 2x as an economy and scent control measure but until then, its much more reliable to stick to the 1x. 2x IS is fine though - You will probably find you need more than one spray from the off and it does not contain none, so OD is not so much of a problem.
I’m afraid we can’t say how many sprays of this and that to start off with as that very much depends on your own body chemistry and range/type of social interactions.
Have a good read of this thread - It covers all the basics on using pheros effectively:
As for mixes - Ammo and IS will be great for the younger women, who tend to go for a more balanced social/sexy/playful signature, whilst A314/TUTH will be better around the older ones who tend to mature to a more overtly sexual/status signature. You can add IS to this as well but TBH, to many of us the simplicity, strength and directness of the A314/TUTH mix is a beauty to behold. 