No hehe
What i meant was that you fill the tank, and then every one or two days, you take 20% out and replace it with "new" water (bottled, aged tap water, whatever).
Here is a little piece of advice that i hope you don´t mind me giving: tell the petshop to cancel the order xD
That will allow you to take time to set the tank properly...think about what you want to put in it, cycle it, etc.
Also, there´s a second reason for me to recommend that you do not purchase those newts, and that´s because pet-shop newts are WC(wild-caught). Being WC means they have gone through a horrible importation (crowded, no food, unsuitable conditions...) during which many die. Those who survive are stressed and often ill. Even those looking good and plump may sucumb to illness because of the stress, and it´s common for them to die shortly after being purchased. Some obviously do very well, but there is always a risk when buying WC animals.
If i were you, and since you are a beginner, i´d look into getting some other species, one that´s easy and CB(captive bred). Pleurodeles waltl is an excelent choice (
http://www.caudata.org/cc/species/Pleurodeles/P_waltl.shtml).
There are breeders in this forum that can provide you with CB, healthy animals of this and other species.
The choice is yours, obviously, but if you want to make a good start in this hobby i strongly recomend what i said above..you certainly won´t regret it!!!
By the way you can find quality information on cycling and many other important things like foods, substrates, etc, in the articles in CC. Make sure you give them a look.