Click M to bring up the material editor (since I don't see the icon on your window). At the Editor, click on the icon of a cube with blue-white checkered pattern. That should show the texture.

That was assuming you've loaded the texture. You will know if you've loaded it or not by looking at the balls at the Material Editor. If there's one ball with your texture on it, you have loaded it. If you haven't, at the Material Editor window there's a small button (square) with the letter M on it (it's on one of the roll-down menu). Click that to choose your texture.