excavate, lavish. then bring in RC material, water with garden hose, compact with vibrating plate (new from €300, buy, use, sell. cheaper than rent)
then set curbstones in concrete. your paving needs support on the left and right. you can also set the outermost row of paving stones in concrete. then more RC in the middle and compact again. then gravel. then level with water. then pave. then vibrate. done.
if I were you, I would have asked the question BEFORE buying the stone, and solved it with gravel grids and decorative gravel...
you need:
concrete in bags (screed cement) 25 and 40 kg often cost the same, but 25 kg is easier to handle.
concrete mixer
concrete tub
shovels + spade + trowel
elbow grease
spirit level (2m (norma) and short and string level)
heavy fat rubber mallet or club with rubber buffer
wheelbarrow(s)
many tons of RC. no idea. 30?
gravel
concrete curbs
string and steel rods
marking spray
a fat angle grinder with diamond blade (the one from norma with segments rocks)
with two lanes, the amount of curbstones to be set, curbstones and required concrete doubles.
your life will be significantly easier if you borrow a mini excavator or micro excavator for a day to excavate, and a compact loader like the AVANT for a day to distribute the gravel and remove the sand excavation. it can also lift a ton, and when the curbstones and concrete are on pallets, you can practically distribute the pallets so you have to carry less.
any idiot can drive a wheel loader, that's fun too.
operating an excavator is more like brainfuck with all the levers and dimensions.
if you're already at the beast, do the infiltration at the same time. nicely bury slotted drain pipe wrapped with fleece next to the path.
have fun. chill enough non-alcoholic beer.