A bit of advice from me. Get a stand alone modeler. This can serve you well later. Even if you get a high end app having a mdeler wher ethe tools for modeleing and nothing else at yrou fingertips is very handy. Keeps the clutter down and generally they are freindlier to the various formats so you can share better. I use Wings because I liek i ta lot it is prices as free. I have Hexagon too it is collecting dust but it has some uses.

Modeling types.
Box modeling think of a lump that you shape by cutting and pushing.
Spline modeling think of the ribs of a ship how they are laid out and connected.
Patch modeling making squares and attaching them to each other till you make an object.

Some free modelers for you. Wings my favorite . Metasequoia a very easy to use spline modeler but to get all the options you have to live in Japan. S-Patch JP-Patch Hama patch all free patch modelers. Anim8tor has a lot of features and is a decent modeler. 

Blender is a full featured program like 3DS and the liek it is free if you use wings it can import wings models easy so it works well with that . Blender has spline and boxmodeling features.

The wit of a misplaced ex-patriot.
I cheated on my metaphysics exam by looking into the soul of the person next to me.