I do not like the youtube link showing how to do a grid in photoshop. It is really archaic, drawing line by line etc etc.
I have a portrait that I need to draw grid over. Is there a simple way in Photoshop CC?
Yup, yes there is. And here's how:
View -> New guide layout and there you can define your grid the way you want.
View -> New guides from shape, a more complex method of doing your guides, but it may suit you best.
A plugin called guide guide, just type it's name in any serach engine and you'll find it (unfortunately it's not free to use - costs 10$, but comes with a lot of handy presets).
Hope that helped!