Preview the new and modern Office for Mac. You will receive regular updates automatically until the official release in the second half of 2015.
Office 2016 for Mac is powered by the cloud so you can access your documents anytime, anywhere, and on any device. It's unmistakably Office - but thoughtfully designed to take advantage of the unique features of the Mac. The new apps offer full retina display support with thousands of retina-optimized graphics, full screen view for native immersive experiences, and even little Mac affordances like scroll bounce.
The new Office 2016 for Mac includes updated versions of Word, Excel, PowerPoint, OneNote and Outlook-and the moment you open any one of the apps, you'll immediately feel the difference. We've modernized the user experience and made it easier to get things done. The redesigned ribbon intuitively organizes features so you can quickly find what you need quickly. A refreshed task pane interface makes positioning, resizing, or rotating graphics easy so you can create exactly the layout you want. And new themes and styles help you pull it all together to produce stunning, professional documents.

Apple has 'iWork' and that did not come with your iMac. It is like 'Office' but made for Macs.
'Pages' is the program that is like 'Word'. 'Numbers' is the program that is like 'excel'
Buy iWork. You will be happy.
You can also buy MS Office for mac. You will also be happy.
Niether of these come with a new Mac. Both are around $100 new.
As far as partitioning: Yes, use 'bootcamp' (in your 'Utilities' folder). Go buy a copy of Windows, and open 'bootcamp', put Windows in your cd drive... presto.. you can run windows all day long.
Hope that helps.