Modeling starts with making faces. There are some ways to make faces and I will introduce them to you here.
Click four times on the 3D view, and a new face is created. Or, click three times and click a right button, and a new triangle is created.
When you click near the existing vertex, a vertex of the new face is shared with the existing face. It is certain to share vertices while pressing the Ctrl key.
[Create] command requires four clicks, and it's a little troublesome. When a face has already existed, select a line and drag it in [Pull] command. It is very easy to make a face that contains first selected line.
[Pull] command makes a quadrangle, and [Create a triangle] in [Wire] command makes a triangle. Select a line and drag it, and it makes a new triangle that contains first selected line.
You can make a basic shape like a cube, a sphere, a cylinder and so on by [Primitive] command.
You can create smooth faces like pulling against each other when you use [Blobs] command.
You must polygonize them after putting blobs.
It can make smooth patches from polygons for realtime. (Faces must be quadrangles fundamentally except Catmull-Clark.)
Select the menu - [Panel] - [Object Panel] and push a 'Property] button. A setting dialog is shown, so select 'Spline Type1/2' or 'Catmull-Clark' in 'Patch' group, and push a OK button. Polygon are displayed as smooth patches. It is possible to operate as before, you can edit an object easily.
If you want to convert patches to polygons, select menu - [Object] - [Freeze] and freeze them with checking a 'Patch'.