My highest is 30.75 secs

However I try this method and I don't understand how to orient the corners...

This step alters the corners so they are all in the right place, but not necessarily in the right orientation, like this:

This is just an example - your corners may be in a different orientation once you've done this.

First thing to do is to examine your cube and see if there are any corners that are already in the right place, e.g. the red, blue and yellow one in the picture above. It's in the right place, just not the right way around. If there are, make sure you hold it in the bottom right corner of the top face when you apply the algorithm - but don't move the top layer, move the whole cube to put it there. If there aren't any correct, you can apply the algorithm when the cube is held in any way (yellow face on top of course).

The algorithm is this:

U R U' L' U R' U' L

Some people (including myself) prefer to think of this as the top face, the right side away, the top face back again, the left side away, top side back again, right side towards, top side back again, left side towards. After the algorithm, the corner cubies (except the one in the bottom right - your possibly correct one) will have changed around. If they still aren't all correct, keep applying the algorithm until it is. If you started with one correct, you'll only have to do this algorithm twice. If you didn't, it may take more.

My Question is what face will be my front face in this situation? I think it's there is this but I am not getting it. Anybody can explain me this??

The whole solution is here :http://www.solve-the-cube.com