I'm a retired Delaware State Trooper. I started a long time ago, 1969 when we only carried a six shot revolver & twelve spare bullets, loose, not in speed loaders. We did carry a box of shells in the car that you could get to if things were to get real bad. We did not have any vests back then either.
Do you have a kevlar vest? That should be one of your first purchases. I would also carry at least two extra mags. Good luck and keep your head down.