EnergyPlus and any of the interfaces (even if producing by
creating an IDF) will produce graphs of the results. These files
are read in by spreadsheet programs and those programs actually produce
graphs. The important thing is not the graphs but the results in
them.
You introduce the size of the building in any of the interfaces by
describing the geometry.
You should use the tutorials:
If you are familiar with building simulation already, you can use the
200+ example files that come with the program along with the Input Output
Reference (which describes each input and output) to help you.
If you are not familiar with building simulation, we suggest you
start with the "Getting Started" document and work through the
tutorial examples there.
In addition, there is an online tutorial,
http://www.vibyor.com/tutorials It's a brief tutorial made by Prof. Vishal Garg, from IIIT Hyderabad,
India.
There is also a forum on vibyor where the participants of the course can
discuss their problems.
If you want to bypass all that and just generate an example for your
building that you can start using and learn that way, you can use the
EnergyPlus Example File Generator application at: