Thank you so much for posting, @Joy!
I think it’s great you’re working with the backing track. And your timing is spot on. Developing your ears is such an important skill, both for tuning and rhythm, and I’m hearing good things.
Here’s a question I’d hate to ask, but what kind of equipment (clarinet, mouthpiece, reed) are you using? I hate to ask, because equipment is not the most important thing. And I certainly don’t want to tell anybody that they need to make a huge investment that may (or may not) improve their sound by a lot (or a little). But having the right amount of resistance, allowing the player to use proper breath support, is important for getting all those overtones and creating a richer sound.