That looks great!! If you want to make it go farther, do the following, make a slight curve along the leading edge that gets wider as you approach the fuselage. The curve should never go past the first 1/3rd of the wing. You want to try and make a slight looking "S" shape.. Do the same, but much more slight, for the elevator. You will be able to get 30 or 40 meters out of it. Make sure the center of gravity is forward of the center of lift on the wing, that would be about half way down the wing on this plane, which means if you support the plane by this point on the wing (the line in the middle of the wing of the picture you posted) the model should tilt forward a fair amount, but not a lot. The pictures below explain it better. You only need for to the top of the pictures, as your wing is a single sheet, it it is double, don't create an overly thick wing as it will create much drag.