Most Bacterial Leaf Spot is brown in the center and surrounded by yellow. You may have something else, possibly fungal, or even worse, viral. Might be insects too as suggested earlier.
If you already have copper spray, go ahead and use it, coat both sides of the leaves. If the problem gets worse, then turn to a sulphur-based spray, or Daconil, which is geared more towards fungal issues. There are also products that combine copper and sulphur, the label will say "copper-sulfate".
If that plant is in a container, move it away from your other plants. And, unless you are spraying treatment, keep those leaves as dry as you can since moisture makes the problem worse.