replacing crazy paving pathway with smooth concrete

[andreafabric]

I have a crazy paving path running down the side of my house, which is about 5" higher than next doors pathway. There was a badly leaning boundry wall which I have removed. There appears to be no footings (probably why the wall was leaning). I want to replace the wall with sleepers, and the path with concrete.
Here's where I get fussy! I want the concrete to be smooth and sandy coloured (to match the london yellow stock bricks of the house, possibly with a little artistic detail like cobbles or large cotswold gravel. I thought the addition of this sort of detail would help by allowing me to do smaller sections at a time and mix the concrete myself.

Do I need to do the sleepers down the side first?

What agregates/percentages do I need to get a smooth sandy coloured finish?

How much do I need to dig down, and what sort of prep do I need before I think about laying concrete?

As you can probably tell, I am a novice at outdoor diy jobs so any advice would be appreciated!