Water Cooler Installation

Hi, i was considering either getting a regular cooling fan or going for something more high end like a water cooler (possibly like an H100 or H80). This question might sound stupid, but do the water coolers come with the water preinstalled? And if not how would i go about putting the water into it, and how complicated would that proccess be? Thanks for any possible responses.

all closed-loop liquid coolers come pre-filled, and do not need to be filled.

also do u know if i need to check it for leakage or anything along those lines

yeah, always a good idea for any liquid cooling.

Also it's worth noting that the the fans that come with the h100/80 are halfway decent.