Test the soil. If the soil has not been tested, conduct a soil test. Call your county Cooperative Extension office for a soil test kit. Lead is a poison and if it gets into the plants, it will get into your food. Plants will not grow well in soil that is either too acidic or too alkaline.
Nutrient levels determine how well plants grow.
Get the tools. Long-handled shovels, gardening spades, spading forks, hoes and rakes are all excellent tools for beginning a garden. If the group doesn't have their own tools, find someone who has what is needed and ask to borrow the tools. Or check yard sales for good quality used tools. Prepare the soil.