The foundation or the source of singing is the breath. If a person knows how to erect the posture of the voice in the breath of inspiration which is found in the yawn or the call they can sing. The first step in learning how to use the voice is to use it comparing a call and a yawn.
Notice that there is a difference between a call and a scream. The scream pushes air out with an outward breath sometime with great force. The call is a beckoning and just as loud as a scream but uses an inward breath.
That inward breath is like the inward breath of the yawn. Singing loudly is as easy as calling and easier than singing softly. Softly requires more control.
If you have trouble recognizing pitches or can't sing on pitch [people suggest that you should not try to sing, don't believe them!], begin to learn how to sing by understanding that it is futile to try to sing on pitch if you don't know what the pitch feels like. The reason is because the feeling of the pitch is stable once you learn how to recognize the pitch as that feeling, and because trying to hear the pitch is always after you have made it.

You are welcome to arrange for a session of live online video conference so we can discuss your needs and how to achieve the goal of singing with self assurance and joyful fulfillment.