I had to learn what to do by myself, trial and error and Google. I use it for sleep medicine since I have always had insomnia. I only get Indica and in the 90% THC. I smoke right before bed and when I wake up every few hours. I like it since I don't have to use a lighter like I did with a pipe, joint or bong. I keep notes and track how much I use, spend, etc wince I am on a very fixed income.
The problem I have had is with charging the battery/pen as well as the packaging of the cartridges. I can never open them and have to have the people at the store open them for me, and sometimes they can't even do it! It is for child protection but when adults can't even open them you know they have gone too far. One 1 gr cartridge lasts me about 3 weeks and is the same price as the actual buds. You have to be careful when charging a pen. After going through one charger a month the staff at my dispensary finally suggested one that I have found to last (6 months so far). It is a "Select" charger that you plug into the wall charger and you screw the vape pen into it before you plug it into the wall. Also, in the winter months the stuff in the cartridge gets thick and you need to warm it up a little (I stick it in my sock while seated and it gets warm in a few minutes). I only need two hits so it works fine for me.