What note is this?

For a few weeks now, I have been trying to play the trombone. Self-teaching. I have to admit that I am a little lost controlling the overtones. And where they correspond in the bass clef notation.

I have sheets of notes I want to play, now I need some way to tell what note I am actually playing. First I googled, then I asked Claude to look for me, eventually Claude custom built it for me:

🪊🎵 The Staff Tuner 🎵🪊