I have been taking Kobi to Point Pleasant Park on Sunday mornings since he was about 4 months old last year. We let him off leash in the off leash areas and walk our way down to the off leash field area near the water. Walking down to the off leash area is still a bit of a challenge where it's usually first thing in the morning, there are lots of other dogs and Kobi is very excited.
I like to try to get Kobi to work on a stay while I unclip his leash and walk away, but I also try to make it fair. If there are lots of other dogs running around and I know it's too hard then I don't bother.
Check out the focus!!
Keep working at it and it will pay off! I always find it amazing how one day things just seem to click for dogs. You struglle for so long then suddenly they just get it and are able to do it.