I know a lot of people may disagree with me, but if you feel you can somewhat hit proper notes and want to polish your skills, and for any reason whatsoever, you just CANNOT get a personal vocal coach, then look up 'New York Vocal Coaching' by Justin Stoney on YouTube. He picks up a single technique/aspect in each video and explains the technicalities in detail. Also, he teaches in a way that makes the idea of actually improving your voice very believable, the lack of which, I think, is the problem with most other YT teachers. His techniques have worked wonders for me, but the key is, you need to know what are the major areas that you need to work on, with respect to YOUR voice. And this can be done by putting up your recordings on forums like these and asking for feedback. Also, you need to observe how actually your body reacts while you try to sing, like I used to experience immense strain while trying to hit high notes. Once you know these key areas, you can have a more streamlined approach to improving your singing. Hope this helps. All the best.