Unfortunately your iron is no longer available in the shops, which means that an instruction booklet is not online. I can give you some info from my wife's steam iron, and I hope that that is of some use to you.
This info relates to a Philips Azur steam iron, model GC4310.
1. Fill with hot or cold water? Fill the water tank with tap water (cold) up to the maximum level by means of the filling cup. Do not fill the tank beyond the MAX indication.
2. Do I do anything other than iron with it? With the Azur, you can use it as a dry (normal, without using steam) iron, and you can use it for steam ironing. The Azur also has a Spray Function. You can use this function to remove stubborn creases at any temperature. Make sure that there is enough water in the tank. Press the spray button several times to moisten the article to be ironed.
3. The Azur has a special button for delivering a shot of steam to remove stubborn creases. You can use this feature with the iron in a vertical position to deal with hanging clothes, curtains, etc.
You can see some of the features of your iron online. Enter Crown CR13888 into Google, and you should get a comparison report of your iron against other brands. The features are listed there.