I'm still a noob myself, but I researched the whole issue for about 4 weeks before diving in.
You can always just buy the battery and prefilled cartomizers. Cartomizers are cartridges that have the heating coil built into them. Most of the commercial prefilled systems, like v2, or blue, work that way. Prefilled cartomizers, however, might sometimes come already half dry, because they might have been stocked for a while.And they only come in a limited selection of flavors.
So, the next step is to buy an empty cartomizer, buy some e-juice, which is the liquid that goes inside there, and do it yourself. I was a bit hesitant first because I thought this will be quite a task to do. In my few days I have been doing this I must say its not at all a nuissance to me - it becomes more of a nice "ritual" that I do in happy anticipation of my next vape hit. The easiest way is to take out the mouthpiece and drip the liquid in the white filling material of the cartomizer. The advantage is: you are in control of the flavor, of the fill level (no dry cartomizer if you monitor how much you vape) and you save money, as a five pack of empty catomizers runs usually somewhere beteen 5.99-8.99$ and e-liquid for 30 ml about 10-15$ and 5 prefilled cartomizers run about 9.99-12.99$.
Cartomizers, at some point, have to be tossed, though some people clean them and get more use out of them that way. I have been using one Cartomizer since I bought the system pretty much continually and it's still working fine.
So, this is the 2-piece type of equipment, like the kr808.
Then, there is the 3-piece type of equipment, where you have the battery, the atomizer, and then a cartridge/tank/clearomizer. That means the heating coil is outside of your tank. Again, from time to time you have to toss the part that holds the e-liquid, or "rebuild" it, that means some people put their own wick in the tank and reuse the tank - that's way too advanced for me though. And the atomizer needs to be replaced from time to time too.
And even the battery is not forever, so at some point you have to buy a new one, just like your cellphone battery runs old, the e-cigarette battery does to.
As to how long the batteries last, the indication for that is the mAh. Mine are 280, and they last me about a whole day, but I have only been a half a pack a day smoker before. The higher the Ampere-hour usually the bigger the battery gets as well.
I am unfortunately not in Europe and have no idea what supplier could get you a decent starter kit, but maybe somebody else can chime in for that. I have the Kr-808D, but most people here prefer the 510 Ego, it seems. However, there are also adapter screws available, if you buy one system you are not "doomed" to stick to it forever .
Welcome to VT. First off the cartomizers that screw into the battery are disposable but can often be refilled many times before there is significant flavor loss. There are so many options to screw into the battery. You have atomizers, cartomizers, clearomizers, etc. They are all basically disposable after some use. Now, to your second question I'm not sure about shipping. As far as most people here we will recommend an ego "style" setup this will be a larger battery than you are used to but it has many benefits. The biggest benefit is the life cycle of the battery. You can get some that will last several hours to ones that last all day long. It's a trade-off though for battery life vs looks. I would recommend something like an ego and tank of some sorts either carto or vivi nova for "long journeys" as they typically last me most of the day before needing to be topped off. I know this is very generic advice but I hope it helps somewhat. Happy vaping.
