I think you're right with that one. I forgot that a tube is a Standard Primitive.
Titan speaks the truth, extrusion is a very important aspect of modelling, and to imagine the mesh as a lump of clay that can be moulded is definitely the way forward. Just creating random objects and merging them together is inefficient and messy, but learning the more complex methods will come to you later.
One thing I will say though :
Editable Poly > Editable Mesh
Editable Poly not only has more advanced tools than the Editable Mesh variations, it also has tools extremely useful for 3D modelling that Editable Mesh does not have.