Problem learning singing? Everyone sings; perhaps in the shower or the car but you sing it loud humming words you do not know. Most people wish they could sing like the newest artist on a top ten list. Parents send their children to voice lessons hoping they will be the next star. It is hard when you do not know what you are doing with pitch, tone, and all the other vocal jargon. I bet you lose your breath on a simple song but you watch artist jump around on stage without a flawed note. Wonder why? It is in your breathing and muscle training. You have to practice everyday on the way to becoming a singer. Even if you have the lungs for it can you hear your note? Vocal coaches teach everything you need to know about singing along with correcting your mistakes.
Maybe your problem learning singing is because you did not know breathing exercise is important for you to sing those notes you have failed to hit so many times before. In school music teachers always say "from the diaphragm" you looked around singing like normal; when you should have been expanding your stomach opening your airway standing up straight. If you work your lungs and stomach muscles everyday you will be prepared for songs without losing your breath or breaking a long note.
I was once told "if you can hum it you can sing it" well we have all hummed along but when we try to carry the note out loud it does not work. Piano notes will help you learn where your voice needs to go. If your ears learn what a high C is then your body will know what pitch you need to be in as a song floats in your ear. Your vocal cords needed to be worked in order to produce the sound you want without braking or cracking mid note.
A vocal couch is the best way for you to sing proficiently but if you are not looking for a career practice will help along with a piano to help with keys.