building off that person's chord-finding question, what are your recommended next steps after achieving the skill of being able to play a note that you hear on your instrument? I can do that, but my issue with chords is that I'm never 100% sure whether the chord I've transcribed has too many notes or not enough. When I'm in the process of adding notes to the chord, there are definitely some that are obviously not present in the chord. Other notes however sound "good" but I wonder if they are actually there or are just "compliant" with the chord and are effectively coloring it in a way that sounds nice. As for not having enough notes in the chord, that is a mystery to me. Maybe that problem isn't as bad though because at a certain point you've gone through all the notes in the scale allotted to that chord in a certain range of the piano and hopefully any significantly lower/higher duplicates of those notes would be obvious to pick out.
don't include any notes you don't hear. after about 5 to 10 songs, you will suddenly start to 'get it.' after 100 to 1000 songs you will start to understand things even more. it's like learning a language. the first time you try to understand it you are definitely not going to get all the letters or even all the words. but if you spend enough time with it, eventually you will know it so well that you will be able to finish other people's sentences