Manhattan is a very walkable area and there are many housing and shopping options near campus. However, if you are looking to get across town check out the following resources for public transportation:
Manhattan's main public transport has route all over town and many across campus.
Manhattan's free bike sharing program has stations on campus and at popular destinations around town.
Local taxi services in the Manhattan available throughout the Manhattan area.
Uber is also available in Manhattan.
Royal Purple Transportation offers private car service to Manhattan from Manhattan Regional Airport. It is a $30 flat rate, plus 15% service charge. Search them on Facebook!