Alright.
Alright, this is more my expertise. I play trumpet/coronet! :D
First off, you actually don't sound half-bad. It's a little amateur sounding, but not actually bad. Your tempo is ALL over the place, but I like the certain jazzy-ness that came in throughout it and how you tried to make a boring old C scale sound interesting. To improve your sound, I suggest good old buzzing and breathing practice, as well as lip slurs and Remmingtons (sp? I've never seen that exercise written before...)
Trumpets and coronets are noble instruments and a good choice if you have an ego big enough to fill it! :D (Band humor.)