You are absolutely going to love the AKL Concierge!!!!!
AKL is our favorite resort!!!!
If my memory serves me right the turndown service typically starts around the dinnertime - early evening period.
As far as when you can use the lounge on arrival day - is as soon as you get there.
We took a redeye out from California and arrived at MCO at 6am - and we were able to use the lounge immediately. Just a note though - our room wasn't ready til 430pm.
Don't miss the Sunrise Safarai - its a must do!!!!
Have a great time - I know you will