Running a terminal command line with "adb install" only works if you have a real Android device connected to your computer via USB.
You select RUN from the menu in Eclipse then select RUN AS ANDROID APPLICATION and the virtual device manager appears then you select your virtual device then launch it, wait a couple minutes. If the virtual device doesn't load then you've probably got some sort of file/folder permission issue. If it does and the console IN ECLIPSE says it can't install the APK then you've probably also got a file permission problem.
Once the virtual device is loaded and running the app should automatically load after you unlock the virtual device's lock screen. If it doesn't then the app icon can be found in the virtual device's app tray which is usually a circle with dots in it near the bottom of the screen.
Do not load the virtual device from the manager and try to manually run ADB from a terminal command it won't work.
You are asking for troubleshooting and will only receive suggestions from people because this method works for others. No one can give you an exact answer to your question without much more information and even then they still need to give you suggestions to try. Also your original question is extremely vague. If for some reason you're set on trying to use ADB then just try "your path to adb"/adb devices
that will show you what devices are connected to adb. If none then that is expected because you don't have a real device connected to your machine!
If you're willing to pay for this information then that's up to you. You could also try StackExchange.