New to singing, or returning after long break, or generally lacking confidence. Note that if you really cannot hear or hold notes, you may need some private training before beginning to learn singing.
You can hold a tune, and know your chest voice from head. Now you need to improve your technical abilities and develop your ability to deliver a song with all notes strong and clear
You have a good grasp of how your voice works, there are no notes you don't understand how to produce, but still you need to become a bit more secure in your execution of demanding passages. You also need to develop your other singer and musician skills, such as performance and harmony.
OK you can do it all. Now you need to make that difficult transition from good singer to industry-ready professional. No mistakes, no hesitation, nothing too difficult for you.