Hi I am one of the experts here on Just Answer.com
Is the something specific about Sketch up you need help with?
There are several ways to select something. Try some of these steps
1. If you single click a surface - it highlights the plane
double click a surface - it will highlight the plane and bounding lines
triple click a surface - it highlights all adjoining faces and lines
2. If you have something that is sticking to everything else around it, the easiest way to move it is to highlight it all, group it, edit the group to cut out everything that is not part of the object, Then you can move it or grow it without affecting things around it.