Paving and Drainage DIY

Hi guys! Since it's slowly getting warmer, some outdoor work will probably be coming up soon! Before I start working wildly on it, I would like to hear a few opinions from you first. The following needs to be done: 1) Set curb stones 2) Spread and compact mineral concrete 3) Pave terrace and parking spaces 4) Build retaining wall 5) Garden shed Priority is first to pave the surfaces to keep all the dirt away from the house. For that, I should first set the curb stones and then fill up with mineral concrete. Can you leave the mineral concrete as is after compacting, or do you have to immediately level it with grit and pave? (We have already roughly backfilled and compacted during the earthworks; it's now quite bumpy.) Should the drainage channels be set beforehand and compacted around them? At the parking space by the street, we should definitely install one; how about on the terrace? By the house or by the wall or both? I have a wastewater connection at the heat pump, but that would require quite a lot of digging and laying in a curve right now. Would it also be an option to simply connect to the existing house connections? (Basically just cut out a piece and install a Y-piece.) Thanks in advance for your impressions Marvin

What can be seen in picture 10? The KG pipe is quite flat...

Image 6 = right drain gutter
Image 10 = left drain gutter

I haven't completely dug it out yet, just wanted to check which direction it goes, or if there is even a Y-distributor somewhere like with the heat pump.
There should also be a small distributor in front of the house, but I have to dig deeper there!

Here again a picture of how it looked after the earthworks without roofing.

It should be laid directly in the frost-free zone, that means deeper than 80cm. Otherwise, everything will freeze up on you.

I will not go deeper than 50cm, for that a steep slope would be possible. (Depending on where I connect...)

A 50cm thick gutter is sufficient, even if it does not meet the standard.