Yeah, you should definitely calibrate the battery.
And, if you are getting an SSD-equipped MBA, you might want to consider following the steps in this thread, if you have some time to perform an OS X reinstall:
https://forums.macrumors.com/threads/427768/
Following these steps can save you 7 GB or more of valuable disk space.
You should also download the iStat Pro dashboard widget (through the Dashboard "More Widgets" panel) when you get a chance. iStat Pro tells you all kinds of important stuff, especially CPU temperature and fan speed.