Re-seeding a lawn

[Billsballbag]

It’s been 2 weeks and the germination is going on.

How long do I water it for and when do I give it the first trim.

Ive been told it then Grows like fook if you put nitrogen on it.

 

[Silver Fox]

I sewed two lawns with seed over the last 2 bank holidays. Rained like cook for 3 weeks and it hasn't rained since. First lawn is threadbare but ground is hard and cracked. Second lawn is still sitting in seed form. Maybe a few strands have germinated.
Will cut them when they are a good few inches long if they ever get there.