My patio has for the most part only dirt (it used to be grass). I would like to have concrete laid down but I have a particular situation that I am not sure how to proceed. The main issue is that I have a deck stair (two actually) but the terrain is a bit slopped, roughly about 8 inches height or more on the highest point on the back (where the block wall is - second photo is from the back towards the front). Also, you can see my garage is across side of one of the stairs (the main on on the photo)

One idea is to have the concrete at the level of the first step running all the way from the back to just before the garage door (second picture) and have another level down for the front part.

In essence:

1) How to better address the concrete and the slope.
2) How should I work the concrete and the garage wall. Shall I just have the concrete poured so that it touches the garage or use some drainage system in between. I am thinking how to best protect for rain (not that it rains lots in Southern California)

I will much appreciate your advice.