Shouldnt be a need to ferilize yet
Had mine down for about a 6 weeks now
Make sure you only cut at most a third of the blades when cutting for the first few months to give chance to grow
I did do this but last week went for a shorter cutand now looks a blooming mess...I hope it will come back but looking quite dead in parts and it has been waterered loads ....not happy
don't use any fertilizer, you want to promote root growth, not top growth at this stage, if you apply fertilizer you will be stressing the roots.
The advice about cutting is right, cut it to a min of about an inch. It will take a while to establish, you can use lawn feeds next spring when the growing season starts, but you don't need them in the first year. Oh, and of course keep it evenly well watered.