Does the raspberry pi 2 come with some sort of power supply? When i was reading about it i couldn't find anny mention on it, so i assume i dosn't, but it it cant hurt to ask .
No it does not but most companies selling it have a recommended one
I would get one that has a 2 Amp capacity to allow for added devices and also ensure you buy a very good USB Lead (Heavy Gauge Wires) for a Charging cable is best
You don't get a USB cable either which is why I'm suggesting that too
You get a RPI in a cardboard box and that's it but as the guys have already said the PSUs are very common.
Get one that is over spec for the job and you'll almost certainly have no problem with that end of things.
Keyboards and mice are also extra but you can use any USB ones you have hanging around on other computers
Mine didn't come, but my phone charger was suitable for such use.