First, breathe.
Speaking of breath, many people find it mysterious. In fact, it is the state when sleeping. Or when you look in front of the mirror, breathe in and out with your shoulders completely still, which is basically right. First form this habit (not only singing, but also using this breath in daily life), and then practice and strengthen it with some skills.
Second, pronunciation.
After you get used to using the above breath state, I recommend the simplest vocal exercise: using it means pulling out your natural timbre, and the breath requirements are the same. You can naturally pronounce the vowel "MA" with the feeling of sighing, and you can lift the smiling muscles with your hands and make a sound with the feeling of smiling. Remember, don't hang up your voice as soon as you make a sound, sigh your breath to your chest and make a sound, and stop if you feel uncomfortable during the practice. But take time out every day to feel the sound. During the practice, the oral state should be kept as natural as speaking, but it should be exaggerated: the oral cavity is moderately opened, the soft palate is properly lifted, the Adam's apple is in a lower position, and the tongue is relaxed and flat, which is the feeling of yawning.