It is important that while you are isolating at home that you still try and be active every day.
If you have a back garden, go outside and do an activity that will increase your heart rate. For example, running, bouncing on the trampoline, playing football.
If you are unable to get outside (due to bad weather or you don't have a garden), have a look at youtube (with a parent) for some cosmic kids yoga or PE with Joe or Lockdown 2.0 Wake Up with Joe.
You may have other fantastic ideas for keeping active - feel free to do and then tell your teacher about them!