i live in DFW area of texas and found some pretty white/orange (clay) color rocks at a construction site that I plan to use to build a walk way from my front yard to my back yard. My house is fairly new so I can rip up two sections of bermuda grass sod in less than an hour. The rocks range in a variety of sizes, but I picked out the ones w/ the flat surfaces as I have kids who will be walking on them as well.
Since I am a little new to something like this - I have a few questions:

1) How deep should I dig?

2) Do I level and tamp down the base?

3) Should I use regular sand or concrete sand or no sand?

4) What type of fill should go on top to fill the rest in?
I am not sure I want to fill in w/ mulch or let the
bermuda come back and fill in between. If so - can I
just lay regular topsoil?

5) Any other suggestions? Money is tight, So i want to keep under $100.00

Thank you very much in advance!!