Sowing directly in the plot means you skip many planting steps and chores. For example, when sowing in a nursery, you have to transplant seedlings several times before they’re in their final growing bed. None of that with direct sowing!
However, you still have to prepare the soil well:
Start with cleaning the place where you want to plant. Remove all weeds, rocks and buried roots. If you plan to sow a fresh lawn, till the soil with a rototiller.
Break up clumps in the soil once it has been cleaned, to lighten it.
Add organic matter with manure or seaweed-based soil conditioner, mixing it into the soil.
Rake the soil to break it up further.
Run a roller over the area, without pressing the soil down too much.
At this point, you can choose to water and let the plot sit as is for 2 weeks. This will give any weed seeds time to sprout. They’ll be much easier to control since you can pull all sprouts out right before your direct sowing. This is called the “stale bed technique”.