SOP: Talking about the university
There’s no single right way to do this. The important point is that you show you’ve “done your homework,” so to speak. If you prefer to do that in one paragraph as you talk about your future studies, that’s probably fine. If you want to make an initial reference early on, that’s fine, too. So is mixing the references throughout the essay. But don’t overdo it, and don’t come across as pandering. 

Finally, make sure to save your work carefully, and be thorough in your edits. The last thing you want to do is send school X an SOP that has references to school Y!