You have a Chromebook - me too, they're awesome!
A chromebook is not a windows PC, it is not an iPad - it's something in between.
With a Chromebook you can login to office365 using Chrome just like on a windows PC.
You can also download apps just like a tablet
So the guides on this website for computers and iPads are useful to you.
This is a link to google's guide
I was going to make my own guide- but google made one already.
This will turn your Chromebook from a good device into a great device!