Access to function buttons

Hi, 

I am using Excel via chrome on an Acer Chromebook 315 laptop. I am signed in with my school account. My concern is, I don't have all necessary functions available to me for me to be able to get the full benefits of Excel and complete assignments. Some missing functions include the Header & Footer and Name Range From Selection. Also, when I am entering a formula, a dialog box doesn't appear; instead, Excel directs me to enter the formula within the cell or formula box (which can inconvenience me if there's an option I need to check in the dialog box).

I hope to receive a response soon.

Thanks.