There are a few ways to do this, first, start off with your lowest note and go up as far as you can.
Another great way is start playing the major scale starting with Middle C, C,D,E,F,G,A,B,C and go up or down by half-step.
You will hear which scales are sung with more ease than others and notice when it starts to become difficult.
2. Find your tessitura
-The tessitura is the range where you you feel most comfortable singing, also the higher and lower notes of your range can exceed the tessitura.
-Pay attention to the part of the range that feels the easiest and has the most power to sing.
-What songs do your enjoy singing to and pay attention to those notes. Most likely, it's because you sing those notes well and that is a good indication of your most comfortable range.
3. Learn to use the right singing technique.
-Have good posture and make sure your chest is expanded.
-With lessons you will learn how to breath and use proper breath support. Speaking of breathing, when you breathe in, your abdomen expands out and upon exhaling, it relaxes back in.
-Have an open position in the back of your throat and enunciate the words at the front of your mouth.
4. Practice Songs
-Make sure to warm-up your vocal cords at least 10-15 minutes at the start of your singing session.
5. Pick the right songs
-Pick the right songs for your voice and practice with the recording, once you feel comfortable, practice without it.
-Try a variety of genres, you may surprise yourself!
Remember, singing is a wonderful journey and have fun finding your voice, as always, sing with confidence!