Hello @jramirezmalerv , thank you for reaching out and posting on the forum!
The existing ENET39 network is a modified version of the IEEE39-bus Test system, and it modeled to represent the New England region of the United States. More details about the network could be found on this link.
With that being said; networks, objects and events in SAInt are flexible and can be modified/edited.
Different modifications usually require different procedure to address them. Could you please elaborate more on what you are looking to change/add so we can address them.
Also, I do recommend you to watch the series of videos on how to effectively use SAInt in this link.
I look forward to hear from you.
Best of luck.