A special message for brass players - you can join in with Mrs Downs playing warm up exercises on this video clip. There are a range here, but Mrs Downs is at the bottom. Download it to practise at home.
There are also a couple of free resources which have been released to schools. The Music Marvels one would be good for Year 4 and Year 5 trumpets and Easy Jazzy Tudes for Year 5 trumpets and tenor horns. We sadly don't have the backing tracks.