Start by fishing it!

I assume you want to focus on big LMB in this pond? If not what goals do you have in mind?

If you catch lots of skinny short bass then you probably have a stunted bass population due to lack of forage. If you catch lots of big bass then you don't need to do a thing (if big LMB is your goal)!

A 4 acre lake should be able to grow good size bass if abundant forage is present.

Where in MD are you?

I'm sure the experts will chime in once they get an idea of what you want to do with this pond and what is already in there.