Avoid any running , the accelerando will come by itself as well as the crescendo also, if you feel you will run short of breath. There is the long ending g1, which must be held in full power. But you can breath before it. Do not forget to play the g1 on the F-side to remain in tune. To make the c1 speak loud enough, push the thumb valve lever to play this particular note on the Bb-side.
All notes are open notes.
The last top g2 could be on the Bb-side. Remain strict in tempo even in the long notes, as the conductor will have trouble to follow you with the Wagner-Tuba entrance . Listen to nothing else than your playing. You are the most important person on stage that moment. All the success is yours.