Hi MazzR & welcome!
Some people (e.g. me) have loads of tanks/clearos (the thing the liquid goes in), some have one or two & rinse them out between flavours, and some just dump one flavour on top of another. Do bear in mind that the coil (the bit in the tank that vaporises the liquid) will pack in after a while, usually 2-6 weeks, so you always should have a spare around anyway.
The lingo you'll get used to after a while, I'm afraid there's too much to explain in one post. we did start a "terminology" thread but it died a death.
There's a range of types of battery about, and they tend to fall into 3 main types:
Standard "ego" style batteries, that you just screw the tank onto, press the button & away you go.
Variable voltage/wattage batteries like the vision spinner, ego C twist & Kanger iMOW, where you turn a dial on the bottom to adjust the power output of the battery.
"Mods" where the shape is different & also with most you buy the case/"brain" and add your own specialist rechargeable batteries.
If you're after bling, the Vision spinners can be bought in a lovely metallic rainbow effect (just google Vision Spinner Rainbow for pics), but I think I saw you commenting on a square shaped one called the eLeaf iStick - Poltergoose has a pink one & can answer any questions on them. You also have to bear in mind that the tanks are usually interchangeable; we all have our favourite tanks & they come in a very wide range of prices.
Feel welcome to dribble in questions as & when they come to you 