In soil, no, it is a baby and does not need protein shakes or T-Bone steaks just yet.
Wait until it has 4-5 nodes before starting with quarter strength nutrients, moving on to half strength when she has 8-10 nodes.
In soil, no more than half strength nutrients are usually required for auto flowers.
When growing in soil, a schedule of plain water/plain water/feed/plain water/plain water/feed is best, once you start feeding.
When it comes to watering, give enough until a little comes out the bottom of the pot.
At this size, do not water again until the top 1cm has dried out again.
In 2-3 weeks, once the plant is established, do not water again until the top 3-5cm have dried out.
This can take anywhere from 1-5 days, depending on temps, your plants requiements and the water holding capacity of your soil mix.
One of your fingers pushed into the soil makes the best moisture meter.
Hope this helps, Organoman.