Vinegar in a spray bottle is safe and a natural weed control. Best to spray weeds when the forecast is going to be sunny and warm for a few days. Only spray the weed not the grass. Another natural remedy is to boil a kettle full of water and then pour the boiling water on the weed. In lawns sometimes just removing them with a hand weeding tool works best,just make sure you get all the roots. If you remove the weeds by hand, really rake the grass hard to remove the dead thatch, and rake in a thin coat (1/4 ") of organic top soil to the lawn it really helps to get the grass thicker and healthier so there are less chance of weeds. Lots of new products for lawns now that don't contain herbacides, haven't really checked them out yet. Hope this helps a little.
