I am not a runner. 
So...tomorrow at phy ed we get to run a half a mile
I know it's not that far, but the thing is it's all timed, and once we're done running we have to go through this insane obstacle course, that is a lot harder than the running.
So I need to run the half mile using the least amount of energy possible while also getting a good time.
So. Would it be better for me to jog it and keep up my stamina or run and take small break intervals? Which will make me less tired once I am done?

So...tomorrow at phy ed we get to run a half a mile

I know it's not that far, but the thing is it's all timed, and once we're done running we have to go through this insane obstacle course, that is a lot harder than the running.
So I need to run the half mile using the least amount of energy possible while also getting a good time.
So. Would it be better for me to jog it and keep up my stamina or run and take small break intervals? Which will make me less tired once I am done?