Turn off code generation and general advice

I am using Visual Paradigm Professional Version 12.2 Edition Evaluation License.

I have some complex java android code that I haven’t looked at for a long time and I want to quickly re-familiarize myself with the design. For the moment at least, this is my primary aim. I am brand new to VP and, however unlikely, I want, in the round-trip engineering, to safe guard against accidentally making some change to the model and have that generate code I didn’t intend. Is there some way to turn off code generation for certain?

What is the recommended way to get an overview of the code design, do I simply drag individual classes or packages over to a diagram, what does it mean to show all packages or just fully qualified owner when just dragging one class?

I would appreciate some advice in this. Thank you.