Don't go into vaping without nicotine right after you quit smoking, definitely going to go through withdrawals that'll make you pick up another cigarette. Depending on how much you smoke, adjust the nicotine dosage appropriately.
1 pack per day - 24mg nicotine (some sites have it at 36mg, might be too much but get what works for you)
1/2 pack per day - 18mg nicotine
3-5 cigs per day w/Marlboro lights - 12mg nicotine
Social smoker, occasional cigarette - 6mg nicotine
I personally was a light smoker for 6 years but enjoy mixing 12mg with 18mg nicotine.
BEST ADVICE: Start with a high dosage of nicotine, then work your way down. Your goal is to quit the cigarette, not the habbit! Vaping is harmless, so I suggest you start high and if you want to, eventually bring it down to 0mg nicotine.