Killing weeds in St. August Grass
What to use to kill clover and other weeds?
Killing weeds in the lawn involves knowing first what kind of weeds you need to kill, because they don't all require the same kind of herbicide, or to be treated at the same time, and then you need to make sure the products you use are safe for the type of grass you have. It will require some research, using articles such as these: https://www.gardeningknowhow.com/plant-problems/weeds/
However, you can also rely on expert assistance from the folks at the county extension service. This link will help you find the nearest office: