There's a whoretonne of jargon, and acronyms that seem to be excuses for giving things long names, so don't feel dumb. It's the reason most places do starter kits so you can make one purchase and go (although usually that's more expensive and less optimal than 'jigsawing' your own kit from individual bits.
Essentially, it's just two parts: the top bit to hold juice, and the bottom bit to provide power.
For the top bit, there's a bajillionty different options. Generally speaking, anything that says it's rebuildable and replaceable is a good call (rebuildable meaning you can take it apart and make the wire and wick parts yourself, dirt cheap and easier than you think, but a bit daunting at first), and replaceable means you can take out the 'head' (holds the wick and wire parts) and insert a new pre-built head.
Bottom bit, you essentially have a choice between a basic 'stick' like an ego style (battery screws into the top bit and just goes), fancier 'sticks' that can change voltage to make it give more/less power, mods (like the fancy stick, but bigger and has a removable rechargeable battery and usually shmancy lights), and mech mods (the removable battery version of the plain stick, but which you can tweak once you know what you're doing). Plain non-variable 'stick' ones tend to be dirt cheap and idiot proof, either of the middle two give you room to fiddle and get to grips with voltage/resistance and such fun, and the mechanical mods tend to be more aimed at "advanced vapers" so probably best ignored at first.
Don't be afraid to get a cheap option. You will want to buy stuff once you learn your tastes, so it's fairly impossible to go from nothing to perfect in one purchase.
And yeah, juice is the real biggie. Many many samples is a motto to live by: try everything you can, even if it doesn't sound like something you'd like, and see what tastes good.
Sent from my Nexus 4 using Planet of the Vapes mobile app