Keiper, I'm not sure there is an actual "breaking in process" that is the same for every user and could be described exactly. But there is a process of learning how to use a PV (any) and there is a break-in period on the atomisers until you've burned off the primer and they start really working well, at least in my experience. How long that lasts will depend on how heavily/frequently you
vape.
In my experience, it took a day or two for my attys to really start working well and for me to be able to truly taste the flavors of the liquids without a hint of the primer taste. That doesn't mean they weren't working at all, just not as well as they do now.
You need to learn how to draw on it to produce the best hit for you. You don't say if you have a different PV now or if the 510 will be your first. You don't "smoke" them like you do an analog. The draw is different and hard to describe. Some say slow long drags and I guess that's as good a description as any. You'll learn how to do it
through trial and error and you'll find your best draw that suits you.
There is the charging period and I would recommend you definitely follow the manufacturer's instructions of charging a full 8 hours (ignore that green light and watch the clock instead), use the battery for 20 minutes, then charge for another hour. If you do this and have any problems, you should be able to eliminate low battery charge as a cause. But, you do have to spend pretty much a day waiting for your 510 to be ready which can be a true test of patience!
I think you'll love your 510! I love mine and haven't smoked an analog since the first day my 510 was fully charged and ready to go!