@Jennifer_Chen: @Natalia’s screenshot was of the old v1.0 project templates. You’re now on the new Project Templates 2.0 which are quite different.
@Bastien_Siebman is exactly right - to get to the Schedule Dates screen including the ability to choose whether to skip weekends or not, you have to click on one task’s due date. For more background on this, see Say Hello to Project Templates 2.0! - #77 by Phil_Seeman, and here’s a video illustration of how to do it.
No, actually it is - even though you’re making the selection on a task, the button on that “Set schedule” screen is “Update all tasks”, so the settings do apply to the whole project. Yes that’s incredibly unintuitive, which I discuss in my post linked to above.