You need to understand what the parts of the cube are. It is not 54 stickers. And it is not 27 little cubes. It is 12 edge and 8 corner pieces moving inside a frame of the 6 unmovable center pieces. Each edge has two stickers, and each corner has three stickers. Here's how the pieces look separated.
You can take apart your cube yourself and see how it works. Prying loose an edge like in the photo to the right works on most cubes. The first time you may have to use a bit of force, even using a knife for leverage.
But some modern speed cubes have a different mechanism. For those you twist the edge 90° instead.
This misunderstanding is probably the main reason people find the cube so very hard. Make sure you understand this!
You also have to realise that the center pieces do not move. No matter how much you turn, they always remain in place. This is obvious when you look at the center piece of a dismantled cube.
Note that when you put the cube together again, you want to do it in the solved state. If not, you have a 93% (11/12) chance of getting it in an unsolvable position. And it's no fun trying to learn on an unsolvable cube...