How to teach myself to sing?

Well I was in the choir in high school and our teacher always told us “breath support”, “open your mouth”, “practice”, and “posture”. Breath support is all about using your diaphram to help you in your breathing control. Over time you strengthen your diaphram, you are able to hold longer notes and sing longer lines without the need to take as many breaths as you do right now. She also gave us things not to do before we sing, like drinking sodas or milk, because of the plegm and carbonation makes you burp! Opening your mouth helps you project your sound. Practice is a must, and always warm up before, like how someone needs to stretch before they work out, otherwise you could damage your vocal cords. And posture goes right along with breathing properly and using your diaphram.

I found a site that has some good tips for singing on it and goes into good detail about some of the things I just mentioned and a ton of others! It is http://a2z-singing-tips.com/ Good luck!