A 14g tank is going to be labor intensive and you'll only be able to keep a small fish or two, but other than that it is a fine place to start (I'd rather see a 30, personally).
Put 20# base/dry rock into the tank. Add sand to desired level. In a separate container mix salt with
RO/
DI and then move the water to the display. Put a powerhead into the tank that is at least 150gph.
I would recommend weekly 3g water changes on the tank, especially in the beginning (but after the cycle is over).
For a cycle you're going to take a small coctail shrimp, put it into the tank and wait for it to decompose and disappear. During that time you're going to see cloudy water (from the stirred sand), more cloudy water 1-2w later (bacteria bloom), brown stuff on your sand and glass (diatoms), and then hopefully 0-0-0 parameters. When you get back to 0-0-0 you're ready for that first fish.
For a water change take a 5g bucket, put 3g of
RO/
DI; 1.5 cups of most salt (Reef Crystals measurement, yours may be different depending on what salt you use), a heater and a powerhead into the bucket and mix for 24 hours. At the end of the 24 hours take another bucket just like the first one and fill it with water from your tank to the same point in the bucket that you filled the first one. That water goes down the drain. Take the water from the bucket that's been mixing and put that back into your tank. Water change done. Again don't do this until you have your parameters (at least ammo & NitrIte) back to 0. Feel free to do a large (7-10g) water change after the levels come to zero to get the nitrAtes in check.
HTH.
