Apple MacBook Air software

Hi all

i restored my apple MacBook Air mid 2013 core i5, as the startup disk was full and it was lagging a lot.

when I reset the laptop the software I got was OS X 10.9.5 which is the old software …. am I able to update it to a new software? When I go to App Store to check for updates nothing comes up!

Any ideas on how to install new software for Mac

Thanking you in advance