How do I know what OS my Mac can run?

I have recently deleted all that I had on my macbook pro and reinstalled the OS. It showed two different OS that it was going to install when I was going back and forth on the screen trying to get my log in to recognizing itself. Then it settled on OS Yoesmite. 10.10.5. I am Running an Early 2015 MacPro (Retina 13 inch) Processor 2.7 GHz Intel core i5, Memory is 8GB 1867 MHz DDR3, and the Graphics is the Intel Iris 6100 1536MB. I would like to know what is the highest OS I can run on this device. I have tried going to the "About This Mac" at the little apple up in the top left corner and updating the software from there. It just says no updates available. I don't want to try and install the very latest and then have a potato for laptop. I am more familiar with windows and have been for decades. However I am trying to get this set up for my kid for school next year. Any help is greatly appreciated, thanks in advance.