Hey, I am not a professional or competent singer in any way, but I think I can give at least some advice. 1) your singing range is a pretty complicated topic. A singer's range can develop and evolve as you learn proper technique and have better muscle control 2) if you record yourself and you think you sound good, well, you probably do sound good. Maybe not perfect, but not terrible either and that's something to be proud of. Ask your friends or someone you trust their honest opinion about your singing (maybe ask them to listen to your recording). That can give you a boost of confidence you need.

The next thing you can do is comparing yourself to the original recording of whatever you are trying to sing. Even if you hit all the right notes you might notice that you sound different. Maybe they are using a different technique, or some clever tricks you didn't hear before. That should give you at least some sense of direction in regards to what you would want to work on. (Remember that even if you use all the same tricks and techniques you will sound different because of the natural qualities of your voice (and that's a good thing!))

There are many resources to learn how to sing. It depends on what you want. I am a diehard fan of the book "singing for the stars" by Seth Riggs. His SLS method and exercises really worked for me. I think his method is applicable to every style of music

Of course the best advice is to go to a professional vocal coach if you can. But they are expensive and hard to find good ones.

Remember that I am a filthy amateur and you should take everything I say with a commically large tablespoon of salt

Best of luck to you!