just want to learn how to sing good…
sing well
There are so many factors to singing. First and for most remember that your body is the instrument. You need to put it together to work properly.
Standing straight, with relaxed but straight knees, and chest high. Imagine a string about two inches below your collar bone attached to the ceiling and another attached to your head also pulling you to the ceiling.
Relax, a relaxed sound is the best, because when you are nervous and on stage, your habits kick in so standing with good form needs to become a habit.
Open your mouth and breath from your diaphragm.
Learning how the body works is important, your mouth and sinuses are like the part of a guitar where the sound resonates and becomes rich and beautiful. Practice different ways to say every vowel, find what sounds the best and adjust depending on how high or low the note is. Do not move your head, it will not help you go higher or lower, it will strain your neck and make it worse.
Sing on the vowel, do not close to a "n" or an "m" or an "s" or a "t" until the very last second, and connect words by the consonants if you can, Instead of "and will", sing "ah ndwill".
These things will help, but remember to record yourself and judge your sound based on those recordings, not how you think you sound.
Warm up, and no more than 1 hour of strong singing in a day.