Hi Polly, Dennis is probably the one that can help you the most but I would go with an overlap liner.
After the site is level and tamped, You can place your sand inside to make it easier later.
Set your blocks for the uprights,Your bottom rails. and go from there.
After the wall's up, level out the sand, A step ladder comes in handy to get out. From the outside you can broom over any foot prints and set your liner.
Hope this helps some.