I just want to create categories and sections being sure that if I create 2 sections/categories with the same alias name, they won't have any kind of conflict...

what happens if I make a section called "news" and a category called "latest" and then do the same exact thing?

Hello,

Unless you enable the "Number duplicate URLs" option in JoomSEF, both categories will have the same SEF URL generated, so only one of them will be displayed.

Best regards,
ARTIO Support Team

That's great. I believe I already have that option enabled, so if I write 2 articles with the same alias they'll be differentiated by a number. I'll need to make sure it's the same option for having sections/categories with the same alias...

Yes, it's the same option.

Best regards,
ARTIO Support Team