opening com ports to upload sketches

I successfully downloaded arduino ide for my mac osx yosemite and the blink sketch seemed to have been uploaded, but every time i try to upload another program to reset the uno it gives me an error saying that the com ports are closed. error message posted below. does anyone know how to open com ports on a macbook air? If this isnt the issue please let me know, dying to use the arduino successfully.

Error Message:
Arduino: 1.6.5 (Mac OS X), Board: "Arduino Uno"

Sketch uses 2,366 bytes (7%) of program storage space. Maximum is 32,256 bytes.
Global variables use 200 bytes (9%) of dynamic memory, leaving 1,848 bytes for local variables. Maximum is 2,048 bytes.
avrdude: ser_open(): can't open device "COM1": No such file or directory
ioctl("TIOCMGET"): Inappropriate ioctl for device
Problem uploading to board. See for suggestions.

This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.