Mac 10.8.2 mountain lion

I download audacity 2.02 and unable to work with Mac mountain lion 10.8.2 please advise

Where did you get stuck? Remember we can’t see what you’re doing. Have you used Audacity before?

I used Audacity in window and is great, and wish to install to my new mac ,while open the programme I rec msg that ( " Audacity " can’t be opened because it is from an unidentified developer. ) please advise

To solve the problem, please right-click or control-click on the Audacity application in Finder, choose “Open”, then in the dialogue box that appears, choose “Open”. You will then be able to launch Audacity normally on subsequent occasions.

For more help with Mac “Gatekeeper”, please see:
Mountain Lion: Hands on with Gatekeeper | Macworld .