is it normal for it to load a long time in the browser and is it normal for the music to not work in the browser
No, it's not normal, if it's loading for a long time, but still loads, then your internet might just be slow. For the music, make sure it's turned on and not muted in the settings.
If possible, I'd recommend you just download the game, that way there's 0 waiting time, unlike for the web where it essentially has to download the full game every time you play.