Long story short as an athlete I get to coach a select group of sprinters from my school. However I don’t know what to do (in terms of managing my teammates/athletes while also being an athlete amongst them).
a) What is some tips you can give so I can be a better coach?
b) How do you get athletes to buy into your system?
c) How does one coach while running with their athletes?
Any help with these questions would be much appreciated

Tempo can be done as group runs.
Sprints typically done individually.
So, no real drama.

Buy unto system, tell success stories.