Hi everyone! a while ago, on the sims 3 store (it seems to me!) i downloaded the create a scenario tool, i just never quite understood how it works! is it easy to use? can beautiful cities and neighborhoods be created? tell me your experience? Thank you!

Do you mean Create A World? There are tutorials for it everywhere. Any custom world you use was created using that tool.

If you want to get started on Create A World, this is the tutorial I use. Like tamalinn said, there are many others, but I found this one to be very complete and helpful.