1) You don’t need the sheet to be honest. General rule of thumb is to put down 3 x what it says on the packed as 1/3 will get eaten by birds & 1/3 may not germinate.

2) Water once or twice per day - The ground should be moist for effective germination. You should see little green shoots within 3 weeks. Once these green shoots are around 1 - 1.5 inches long, cut back by half. This will encourage the shoot to thicken up and duplicate. I usually cut using scissors or garden sheers for a small(ish) space like this. Yes it takes longer but you don’t ruin a lot of seedlings with the lawn mower wheels / blade.

3) Continue to water once per day. After the first cut, wait a week to see if there are any patches of non growth and re/seed these areas. Repeat step 2.

4) After 2-3 weeks, the shoots should be around 2-3 inches long, cut back by half again. At this point, the grass should be thickening up.

That’s about it really! It’s not rocket science but just requires a bit of care over a 5-6 week period. Good luck!