The answer to 'sod has weeds' is that weeds in new sod are a common problem, often caused by weed seeds being present in the soil or sod itself. Symptoms include patchy, uneven growth and the presence of unwanted plants that compete with the desired grass. Solutions include hand-pulling weeds, applying selective herbicides, and overseeding with new grass seed to outcompete the weeds.
In general, it's best to call a professional landscaper for significant weed problems, as they have the expertise and equipment to properly diagnose and treat the issue. For minor weed infestations, homeowners can often handle the problem themselves with some basic lawn care techniques.