How to convert the Java code to Kotlin for your App in Android Studio?

Hello sir.
I follow th same steps in my app there is 4 activities and when I convert just on activity face this error can please help me.
Thanks in advance.

Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

Hello sir..
I created an app -which convert text to speech..
But the speech is in female voice and I want it in male voice..
How to do That please help me