Make Rounded Corners?

[NonStopableForce]

How do i make rounded corners, and circle stuff? i tryed doing it with the vertex tool, and anything i can click on, usually i teach my self the programs, by clicking buttons, but there isn't much to click , so i need some help.

-NonStopableForce

 

[Dux]

Primitives > Cylinder

 

[batchetska]

or you could use the clipping tool