1 gal of vinegar 1 cup of salt and a few squirts of Blue Dawn. Mix, Put in a spray bottle and kill away.
This article is really helpful Barbara
Here are some natural weed killers: https://www.countryliving.com/gardening/garden-ideas/g4176/homemade-weed-killer/
The problem with weeds is that you can kill or remove the weed that is growing however there are other seeds that are dormant. Also if pulling weeds in many cases you must remove the entire root system. That being said if you are trying to keep weeds growing in flower beds or planting beds and around trees it is best to place a layer cardboard or several layers of paper over the ground that you wish to place mulch and then place the mulch over the cardboard or paper. The intent is to remove all sources of sunlight and for a time a source of water from weed seeds from germinating. The cardboard and or paper will degrade (note paper and cardboard are made from wood and will discompose the same as tree mulch. In order to keep the weed from growing you will need to add mulch as is decomposes. Mulch layer should be a minimum of 3 inches in depth.