The diaphragmatic breathing will avoid your voice getting sore and tired out, that is why a good breathing technique is very important to have.
Here the short version of breathing support:
1) Lay down on your back and take notice of how your abdominal area moves easy up when you inhale, down when you exhale. No tension and nothing else involved in the process right? Ok, then next step.
2) Standing up, find the same breath process you do, but this time, the gravity is doing its job and there are other muscles involved that allow you to be standing up plus...your chest will be down or collapsed. Then, stand straight, do not over do it, just straight and raise your arms. Get one hand down slowly and find your sternum, get the other hand down and get it where your other hand is. Can you feel how high your chest feels? Right! that is the position we want. Did you move anything besides your arms? If you did, go back and try it again. Are your shoulders relaxed or up? If they are up or tense, go back and try it again.
3) Once you are in a standing straight position, then recreate the sensation of you breathing while laying down...It might seem that you cannot breath deep with this straight position, believe me it is possible, keep trying until you get the same relaxation process you experienced when laying down.
Note: If this was not enough trouble lol! your chest MUST stay up when you release the air.
4) Remember, never during this process you must experience any tension, try this in short sessions of 5-10 min. Once you feel comfortable with this, then you are getting ready to start making sounds. Get back with me and I will give you some exercises. But before anything else, you must master breathing. Good luck and have fun getting to know your body and your instrument!