AI'm new with fondant and don't know much about it. Everytime I cover the cake with it gets hard? Is this normal?

Read the list of ingredients if you buy it readymade. Some of the minor ingredients should be glycerine and vegetable shortening.

If you make fondant yourself, you need to buy food grade glycerine (aka glycerol) and add it using 1 teaspoon (5mL) per pound (450 grams) of sugar.  It slows down the rate of drying.

Buy it from a candymaking supplier or candy craft section, in the US the label will read "USP" if it is edible.

AThe longer you leave fondant exposed to air the harder it gets. On a cake surface this is normal, it will not be brittle just dried out on the surface. If you are applying fondant several days before a cake is due, it is absolutely fine, and will still be softer under the surface.

AMakes the fondant to dry out so quickly. If you are dusting with cornflour, try to reduce it. I dust wit icing sugar. It helps d fondant not to dry so much

FYI I've also heard that Fondarific dries out much more slowly than the other brands but it's pretty expensive.