No offense to you, but if you are a newbie and cannot calculate / use math to mix eliquid, you should probably do some learning/reading first.
This is the bare essentials of DIY.......you have to be able to use math or an ejuice calculator. When you have enough posts please head over to the DIY area of the forum where you can find calculators and help.
I am not trying to discourage you but you need to be able to compute these numbers on a regular basis, and also be able to compute how much the addition of flavoring %'s, as well as other additives like distilled water, extra PG or VG, etc. are going to affect your goal of a 24mg end product.