Bands and grade of therapist vary from country to country, as does their terminology. Perhaps the main issue here is that they almost always relate to working in the Public sector. As a private practitioner working in the area of sports medicine these grades will have no relevance. They are a way to keep the NHS budgets in check, nothing more really. I say this as a person who is a low grade in one hospital because that is the available job and pay grade may find themselves higher or lower in another hospital because or what may be available more than how much skill they have.

I would not focus on such questions now as by the time you graduate the answer will be very different. For now focus on getting into a good physio school and then doing well in your studies. You may even find that by the end of the undergraduate process your interests lie elsewhere