A decision to be made first is do you want to grow an organic garden without the use of commercial fertilizers and herbicides to control weeds. I’m not an organic gardener myself, but I respect the concept. Organic gardening takes a lot more patience than I have.
Organic gardeners must provide needed plant nutrients with organically produced manures, or green manures (plant material grown and tilled back into the soil before it matures like sweet clover). Weeds must be tilled, pulled or burned out. Manures do not work like commercial fertilizers. Composted manures take considerable time for the soil microbes to break the material down to release need nutrients for the plant. Commercial fertilizers release needed nutrients within a few days of application.