How well can I really sing?

So how do i know if I can really sing or not?

Hi, Cadence! In my experience, everyone who can speak can also sing. The question is how well - and I think the most important thing to work on in the beginning is your intonation, since you can have an incredible range and lovely tone, but if you're singing out of tune, it'll still sound "off". Check out this article for some self-study tips, and this link for some ear training app recommendations so you can test and improve your intonation!

Ok! Thank you so much. I have one more question. I'm scared to sing in front of people with an exception of my friends. They say i have a beautiful voice. So last school year i tried out for the musical. I got so nervous, that i started shaking & didn't make it. How can i bring up my confidence level?

I'm sorry you had that experience! I've 100% been there, too. I encourage you to watch this live lesson on performance prep: https://www.youtube.com/watch?v=8E3iU5XCNOY. (I talk about confidence and nerves towards the end, but I think you'll get a lot out of the whole thing). Preparation is my best antidote for nerves; but nerves are always going to be present! The more experience you have singing in front of people, the more you'll get used to singing in spite of nerves. 

Day 27 of my beginner course covers confidence and nerves as well: https://www.30daysinger.com/tutorial/30-day-beginner-course-with-camille/27. 

Ok thank you so much!

My pleasure!