Use the Android logging utility.

http://developer.android.com/reference/android/util/Log.html

Log has a bunch of static methods for accessing the different log levels. The common thread is that they always accept at least a tag and a log message.

Tags are a way of filtering output in your log messages. You can use them to wade through the thousands of log messages you'll see and find the ones you're specifically looking for.

You use the Log functions in Android by accessing the Log.x objects (where the x method is the log level). For example:

CopyLog.d("MyTagGoesHere", "This is my log message at the debug level here");
Log.e("MyTagGoesHere", "This is my log message at the error level here");

I usually make it a point to make the tag my class name so I know where the log message was generated too. Saves a lot of time later on in the game.

You can see your log messages using the logcat tool for android:

Copyadb logcat

Or by opening the eclipse Logcat view by going to the menu bar

CopyWindow->Show View->Other then select the Android menu and the LogCat view

Java doesn't use console.log; it is a totally different language than Javascript. You would use System.out.print or System.out.println instead.

Good luck with your learning!