can someone give me some practise surfacing drawing with daimenstion
Surface models don't usually have dimensions. They are complex, so simple X,Y dimensions are not very useful.
Try making the handle that was posted a few days ago. It was an excellent for surfacing. Just guess at the dimensions, and go back to fix it later if the the proportions are off.
It is great practice for both surface modeling, and editing a part without having it fall apart: