Steep Downward Sloping Lot Parking Questions

[Skye Parker]

Hey All. I'm looking into buying a lot on the downhill side of the road. Its 23' from the edge of the street to the property line. This is heavily vegetated hillside and the slope is about 50% (28 degrees). I'm thinking of providing a couple of off street parallel parking spots with a retaining wall and then building lower on the property with stairs going down to the house. My question is what are the rules on creating parking spots? Can they be right off the street and not on my land?