Hi Burntfish. Welcome to the ECF. For starters you have picked up a great setup to begin your journey into vaping. The vision clearos(a link to the specific ones you purchased would help you get better information) generally last anywhere from a few days to a few months if properly cared for. Most people generally retire the cartomizer/atty/clearomizer when one of a few things happen either lack of good performance, poor flavor(burnt flavor) or just outright failure. Most of the ce style units require cleaning periodically. The way I clean them is to empty the resivoir, rinse the coil under hot water until the wicks look clean again apply to battery and pulse power on and off until I can see the coils individually glowing. This burns off all the buildup and restores performance. This can be done many times until the coil wears out and breaks, at which time it will need to be replaced. Using this method I can usually get about 12-20 days from a single coil, and I generally use about 7ml of liquid per day.
On that note you may want to go ahead and get a few small bottles of liquid on the way. Most new vapers consume anywhere from 2-4ml of liquid per day. While you do have a fair amount of liquid on the way, you never know how you will like it until you have tried it. Finding my all day liquid was quite a task all in its own. I recommend reading some specific threads on peoples favorite flavor or vendor for good liquids. Taste is subjective and what works for me, may or may not work for you. Lots of sampling may or may not be in your future..... Liquids generally have a shelf life, without exposure to sunlight, for beyond a year.
Clearomizers generally are easier to fill than a cartomizer tank. Generally the cartomizer tanks are cheaper to service($1.50 carto versus $3 replacement head) but the clearomizers usually have a longer service life, and can be cleaned and dry burned , where a cartomizer(in or out of a tank) can not be cleaned without going through a fair amount of work to do so. If you meant tanks like the eGo-c or the eGo-t atomizer tanks then I would advise you to search "eGo-c problem" and read through the consistant string of posts pertainig to those type tanks.
If you have anything else just ask, we will try to get the info you need. Good Luck. Happy Vaping.